python第二天,字符串,列表,元祖,字典
1、字符串
字符串创建后,不可修改
每个字符串都具备如下功能:

1 class str(basestring): 2 """ 3 str(object='') -> string 4 5 Return a nice string representation of the object. 6 If the argument is a string, the return value is the same object. 7 """ 8 def capitalize(self): 9 """ 首字母变大写 """ 10 """ 11 S.capitalize() -> string 12 13 Return a copy of the string S with only its first character 14 capitalized. 15 """ 16 return "" 17 18 def center(self, width, fillchar=None): 19 """ 内容居中,width:总长度;fillchar:空白处填充内容,默认无 """ 20 """ 21 S.center(width[, fillchar]) -> string 22 23 Return S centered in a string of length width. Padding is 24 done using the specified fill character (default is a space) 25 """ 26 return "" 27 28 def count(self, sub, start=None, end=None): 29 """ 子序列个数 """ 30 """ 31 S.count(sub[, start[, end]]) -> int 32 33 Return the number of non-overlapping occurrences of substring sub in 34 string S[start:end]. Optional arguments start and end are interpreted 35 as in slice notation. 36 """ 37 return 0 38 39 def decode(self, encoding=None, errors=None): 40 """ 解码 """ 41 """ 42 S.decode([encoding[,errors]]) -> object 43 44 Decodes S using the codec registered for encoding. encoding defaults 45 to the default encoding. errors may be given to set a different error 46 handling scheme. Default is 'strict' meaning that encoding errors raise 47 a UnicodeDecodeError. Other possible values are 'ignore' and 'replace' 48 as well as any other name registered with codecs.register_error that is 49 able to handle UnicodeDecodeErrors. 50 """ 51 return object() 52 53 def encode(self, encoding=None, errors=None): 54 """ 编码,针对unicode """ 55 """ 56 S.encode([encoding[,errors]]) -> object 57 58 Encodes S using the codec registered for encoding. encoding defaults 59 to the default encoding. errors may be given to set a different error 60 handling scheme. Default is 'strict' meaning that encoding errors raise 61 a UnicodeEncodeError. Other possible values are 'ignore', 'replace' and 62 'xmlcharrefreplace' as well as any other name registered with 63 codecs.register_error that is able to handle UnicodeEncodeErrors. 64 """ 65 return object() 66 67 def endswith(self, suffix, start=None, end=None): 68 """ 是否以 xxx 结束 """ 69 """ 70 S.endswith(suffix[, start[, end]]) -> bool 71 72 Return True if S ends with the specified suffix, False otherwise. 73 With optional start, test S beginning at that position. 74 With optional end, stop comparing S at that position. 75 suffix can also be a tuple of strings to try. 76 """ 77 return False 78 79 def expandtabs(self, tabsize=None): 80 """ 将tab转换成空格,默认一个tab转换成8个空格 """ 81 """ 82 S.expandtabs([tabsize]) -> string 83 84 Return a copy of S where all tab characters are expanded using spaces. 85 If tabsize is not given, a tab size of 8 characters is assumed. 86 """ 87 return "" 88 89 def find(self, sub, start=None, end=None): 90 """ 寻找子序列位置,如果没找到,返回 -1 """ 91 """ 92 S.find(sub [,start [,end]]) -> int 93 94 Return the lowest index in S where substring sub is found, 95 such that sub is contained within S[start:end]. Optional 96 arguments start and end are interpreted as in slice notation. 97 98 Return -1 on failure. 99 """ 100 return 0 101 102 def format(*args, **kwargs): # known special case of str.format 103 """ 字符串格式化,动态参数,将函数式编程时细说 """ 104 """ 105 S.format(*args, **kwargs) -> string 106 107 Return a formatted version of S, using substitutions from args and kwargs. 108 The substitutions are identified by braces ('{' and '}'). 109 例如: 110 # 格式化,将一个字符串中的占位符替换为指定的值 111 # test = 'i am {name}, age {a}' 112 # print(test) 113 # v = test.format(name='alex',a=19) 114 # print(v) 115 116 # test = 'i am {0}, age {1}' 117 # print(test) 118 # v = test.format('alex',19) 119 # print(v) 120 121 # 格式化,传入的值 {"name": 'alex', "a": 19} 122 # test = 'i am {name}, age {a}' 123 # v1 = test.format(name='df',a=10) 124 # v2 = test.format_map({"name": 'alex', "a": 19}) 125 """ 126 pass 127 128 def index(self, sub, start=None, end=None): 129 """ 子序列位置,如果没找到,报错 """ 130 S.index(sub [,start [,end]]) -> int 131 132 Like S.find() but raise ValueError when the substring is not found. 133 """ 134 return 0 135 136 def isalnum(self): 137 """ 是否是字母和数字 """ 138 """ 139 S.isalnum() -> bool 140 141 Return True if all characters in S are alphanumeric 142 and there is at least one character in S, False otherwise. 143 """ 144 return False 145 146 def isalpha(self): 147 """ 是否是字母 """ 148 """ 149 S.isalpha() -> bool 150 151 Return True if all characters in S are alphabetic 152 and there is at least one character in S, False otherwise. 153 """ 154 return False 155 156 def isdigit(self): 157 """ 是否是数字 """ 158 """ 159 S.isdigit() -> bool 160 161 Return True if all characters in S are digits 162 and there is at least one character in S, False otherwise. 163 """ 164 return False 165 166 def islower(self): 167 """ 是否小写 """ 168 """ 169 S.islower() -> bool 170 171 Return True if all cased characters in S are lowercase and there is 172 at least one cased character in S, False otherwise. 173 """ 174 return False 175 176 def isspace(self): 177 """ 178 S.isspace() -> bool 179 180 Return True if all characters in S are whitespace 181 and there is at least one character in S, False otherwise. 182 """ 183 return False 184 185 def istitle(self): 186 """ 187 S.istitle() -> bool 188 189 Return True if S is a titlecased string and there is at least one 190 character in S, i.e. uppercase characters may only follow uncased 191 characters and lowercase characters only cased ones. Return False 192 otherwise. 193 """ 194 return False 195 196 def isupper(self): 197 """ 198 S.isupper() -> bool 199 200 Return True if all cased characters in S are uppercase and there is 201 at least one cased character in S, False otherwise. 202 """ 203 return False 204 205 def join(self, iterable): 206 """ 连接 """ 207 """ 208 S.join(iterable) -> string 209 210 Return a string which is the concatenation of the strings in the 211 iterable. The separator between elements is S. 212 """ 213 return "" 214 215 def ljust(self, width, fillchar=None): 216 """ 内容左对齐,右侧填充 """ 217 """ 218 S.ljust(width[, fillchar]) -> string 219 220 Return S left-justified in a string of length width. Padding is 221 done using the specified fill character (default is a space). 222 """ 223 return "" 224 225 def lower(self): 226 """ 变小写 """ 227 """ 228 S.lower() -> string 229 230 Return a copy of the string S converted to lowercase. 231 """ 232 return "" 233 234 def lstrip(self, chars=None): 235 """ 移除左侧空白 """ 236 """ 237 S.lstrip([chars]) -> string or unicode 238 239 Return a copy of the string S with leading whitespace removed. 240 If chars is given and not None, remove characters in chars instead. 241 If chars is unicode, S will be converted to unicode before stripping 242 """ 243 return "" 244 245 def partition(self, sep): 246 """ 分割,前,中,后三部分 """ 247 """ 248 S.partition(sep) -> (head, sep, tail) 249 250 Search for the separator sep in S, and return the part before it, 251 the separator itself, and the part after it. If the separator is not 252 found, return S and two empty strings. 253 """ 254 pass 255 256 def replace(self, old, new, count=None): 257 """ 替换 """ 258 """ 259 S.replace(old, new[, count]) -> string 260 261 Return a copy of string S with all occurrences of substring 262 old replaced by new. If the optional argument count is 263 given, only the first count occurrences are replaced. 264 """ 265 return "" 266 267 def rfind(self, sub, start=None, end=None): 268 """ 269 S.rfind(sub [,start [,end]]) -> int 270 271 Return the highest index in S where substring sub is found, 272 such that sub is contained within S[start:end]. Optional 273 arguments start and end are interpreted as in slice notation. 274 275 Return -1 on failure. 276 """ 277 return 0 278 279 def rindex(self, sub, start=None, end=None): 280 """ 281 S.rindex(sub [,start [,end]]) -> int 282 283 Like S.rfind() but raise ValueError when the substring is not found. 284 """ 285 return 0 286 287 def rjust(self, width, fillchar=None): 288 """ 289 S.rjust(width[, fillchar]) -> string 290 291 Return S right-justified in a string of length width. Padding is 292 done using the specified fill character (default is a space) 293 """ 294 return "" 295 296 def rpartition(self, sep): 297 """ 298 S.rpartition(sep) -> (head, sep, tail) 299 300 Search for the separator sep in S, starting at the end of S, and return 301 the part before it, the separator itself, and the part after it. If the 302 separator is not found, return two empty strings and S. 303 """ 304 pass 305 306 def rsplit(self, sep=None, maxsplit=None): 307 """ 308 S.rsplit([sep [,maxsplit]]) -> list of strings 309 310 Return a list of the words in the string S, using sep as the 311 delimiter string, starting at the end of the string and working 312 to the front. If maxsplit is given, at most maxsplit splits are 313 done. If sep is not specified or is None, any whitespace string 314 is a separator. 315 """ 316 return [] 317 318 def rstrip(self, chars=None): 319 """ 320 S.rstrip([chars]) -> string or unicode 321 322 Return a copy of the string S with trailing whitespace removed. 323 If chars is given and not None, remove characters in chars instead. 324 If chars is unicode, S will be converted to unicode before stripping 325 """ 326 return "" 327 328 def split(self, sep=None, maxsplit=None): 329 """ 分割, maxsplit最多分割几次 """ 330 """ 331 S.split([sep [,maxsplit]]) -> list of strings 332 333 Return a list of the words in the string S, using sep as the 334 delimiter string. If maxsplit is given, at most maxsplit 335 splits are done. If sep is not specified or is None, any 336 whitespace string is a separator and empty strings are removed 337 from the result. 338 """ 339 return [] 340 341 def splitlines(self, keepends=False): 342 """ 根据换行分割 """ 343 """ 344 S.splitlines(keepends=False) -> list of strings 345 346 Return a list of the lines in S, breaking at line boundaries. 347 Line breaks are not included in the resulting list unless keepends 348 is given and true. 349 """ 350 return [] 351 352 def startswith(self, prefix, start=None, end=None): 353 """ 是否起始 """ 354 """ 355 S.startswith(prefix[, start[, end]]) -> bool 356 357 Return True if S starts with the specified prefix, False otherwise. 358 With optional start, test S beginning at that position. 359 With optional end, stop comparing S at that position. 360 prefix can also be a tuple of strings to try. 361 """ 362 return False 363 364 def strip(self, chars=None): 365 """ 移除两段空白 """ 366 """ 367 S.strip([chars]) -> string or unicode 368 369 Return a copy of the string S with leading and trailing 370 whitespace removed. 371 If chars is given and not None, remove characters in chars instead. 372 If chars is unicode, S will be converted to unicode before stripping 373 """ 374 return "" 375 376 def swapcase(self): 377 """ 大写变小写,小写变大写 """ 378 """ 379 S.swapcase() -> string 380 381 Return a copy of the string S with uppercase characters 382 converted to lowercase and vice versa. 383 """ 384 return "" 385 386 def title(self): 387 """ 388 S.title() -> string 389 390 Return a titlecased version of S, i.e. words start with uppercase 391 characters, all remaining cased characters have lowercase. 392 """ 393 return "" 394 395 def translate(self, table, deletechars=None): 396 """ 397 转换,需要先做一个对应表,最后一个表示删除字符集合 398 intab = "aeiou" 399 outtab = "12345" 400 trantab = maketrans(intab, outtab) 401 str = "this is string example....wow!!!" 402 print str.translate(trantab, 'xm') 403 """ 404 405 """ 406 S.translate(table [,deletechars]) -> string 407 408 Return a copy of the string S, where all characters occurring 409 in the optional argument deletechars are removed, and the 410 remaining characters have been mapped through the given 411 translation table, which must be a string of length 256 or None. 412 If the table argument is None, no translation is applied and 413 the operation simply removes the characters in deletechars. 414 """ 415 return "" 416 417 def upper(self): 418 """ 419 S.upper() -> string 420 421 Return a copy of the string S converted to uppercase. 422 """ 423 return "" 424 425 def zfill(self, width): 426 """方法返回指定长度的字符串,原字符串右对齐,前面填充0。""" 427 """ 428 S.zfill(width) -> string 429 430 Pad a numeric string S with zeros on the left, to fill a field 431 of the specified width. The string S is never truncated. 432 """ 433 return "" 434 435 def _formatter_field_name_split(self, *args, **kwargs): # real signature unknown 436 pass 437 438 def _formatter_parser(self, *args, **kwargs): # real signature unknown 439 pass 440 441 def __add__(self, y): 442 """ x.__add__(y) <==> x+y """ 443 pass 444 445 def __contains__(self, y): 446 """ x.__contains__(y) <==> y in x """ 447 pass 448 449 def __eq__(self, y): 450 """ x.__eq__(y) <==> x==y """ 451 pass 452 453 def __format__(self, format_spec): 454 """ 455 S.__format__(format_spec) -> string 456 457 Return a formatted version of S as described by format_spec. 458 """ 459 return "" 460 461 def __getattribute__(self, name): 462 """ x.__getattribute__('name') <==> x.name """ 463 pass 464 465 def __getitem__(self, y): 466 """ x.__getitem__(y) <==> x[y] """ 467 pass 468 469 def __getnewargs__(self, *args, **kwargs): # real signature unknown 470 pass 471 472 def __getslice__(self, i, j): 473 """ 474 x.__getslice__(i, j) <==> x[i:j] 475 476 Use of negative indices is not supported. 477 """ 478 pass 479 480 def __ge__(self, y): 481 """ x.__ge__(y) <==> x>=y """ 482 pass 483 484 def __gt__(self, y): 485 """ x.__gt__(y) <==> x>y """ 486 pass 487 488 def __hash__(self): 489 """ x.__hash__() <==> hash(x) """ 490 pass 491 492 def __init__(self, string=''): # known special case of str.__init__ 493 """ 494 str(object='') -> string 495 496 Return a nice string representation of the object. 497 If the argument is a string, the return value is the same object. 498 # (copied from class doc) 499 """ 500 pass 501 502 def __len__(self): 503 """ x.__len__() <==> len(x) """ 504 pass 505 506 def __le__(self, y): 507 """ x.__le__(y) <==> x<=y """ 508 pass 509 510 def __lt__(self, y): 511 """ x.__lt__(y) <==> x<y """ 512 pass 513 514 def __mod__(self, y): 515 """ x.__mod__(y) <==> x%y """ 516 pass 517 518 def __mul__(self, n): 519 """ x.__mul__(n) <==> x*n """ 520 pass 521 522 @staticmethod # known case of __new__ 523 def __new__(S, *more): 524 """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ 525 pass 526 527 def __ne__(self, y): 528 """ x.__ne__(y) <==> x!=y """ 529 pass 530 531 def __repr__(self): 532 """ x.__repr__() <==> repr(x) """ 533 pass 534 535 def __rmod__(self, y): 536 """ x.__rmod__(y) <==> y%x """ 537 pass 538 539 def __rmul__(self, n): 540 """ x.__rmul__(n) <==> n*x """ 541 pass 542 543 def __sizeof__(self): 544 """ S.__sizeof__() -> size of S in memory, in bytes """ 545 pass 546 547 def __str__(self): 548 """ x.__str__() <==> str(x) """ 549 pass 550 551 str 552 553 str

1 字符串 str 2 ########################################### 3 4 # 1 首字母大写 5 # test = "aLex" 6 # v = test.capitalize() 7 # print(v) 8 9 # 2 所有变小写,casefold更牛逼,很多未知的对相应变小写 10 # v1 = test.casefold() 11 # print(v1) 12 # v2 = test.lower() 13 # print(v2) 14 15 # 3 设置宽度,并将内容居中 16 # 20 代指总长度 17 # * 空白未知填充,一个字符,可有可无 18 # v = test.center(20,"中") 19 # print(v) 20 21 # test = "alex" 22 # v = test.ljust(20,"*") 23 # print(v) 24 25 # test = "alex" 26 # v = test.rjust(20,"*") 27 # print(v) 28 29 # test = "alex" 30 # v = test.zfill(20) 31 # print(v) 32 33 34 # 4 去字符串中寻找,寻找子序列的出现次数 35 # test = "aLexalexr" 36 # v = test.count('ex') 37 # print(v) 38 39 # test = "aLexalexr" 40 # v = test.count('ex',5,6) 41 # print(v) 42 43 # 欠 44 # encode 45 # decode 46 47 # 5 48 # 以什么什么结尾 49 # 以什么什么开始 50 # test = "alex" 51 # v = test.endswith('ex') 52 # v = test.startswith('ex') 53 # print(v) 54 55 # 6 expandtabs,断句20, 56 # test = "username\temail\tpassword\nlaiying\tying@q.com\t123\nlaiying\tying@q.com\t123\nlaiying\tying@q.com\t123" 57 # v = test.expandtabs(20) 58 # print(v) 59 60 # 7 从开始往后找,找到第一个之后,获取其未知 61 # > 或 >= 62 # test = "alexalex" 63 # 未找到 -1 64 # v = test.find('ex') 65 # print(v) 66 67 # 8 index找不到,报错 忽略 68 # test = "alexalex" 69 # v = test.index('8') 70 # print(v) 71 72 73 # 9 格式化,将一个字符串中的占位符替换为指定的值 74 # test = 'i am {name}, age {a}' 75 # print(test) 76 # v = test.format(name='alex',a=19) 77 # print(v) 78 79 # test = 'i am {0}, age {1}' 80 # print(test) 81 # v = test.format('alex',19) 82 # print(v) 83 84 # 10 格式化,传入的值 {"name": 'alex', "a": 19} 85 # test = 'i am {name}, age {a}' 86 # v1 = test.format(name='df',a=10) 87 # v2 = test.format_map({"name": 'alex', "a": 19}) 88 89 # 11 字符串中是否只包含 字母和数字 90 # test = "123" 91 # v = test.isalnum() 92 # print(v) 93 # str 94 95 # 12 是否是字母,汉子 96 # test = "as2df" 97 # v = test.isalpha() 98 # print(v) 99 100 # 13 当前输入是否是数字 101 # test = "二" # 1,② 102 # v1 = test.isdecimal() 103 # v2 = test.isdigit() 104 # v3 = test.isnumeric() 105 # print(v1,v2,v3) 106 107 108 # 14 是否存在不可显示的字符 109 # \t 制表符 110 # \n 换行 111 # test = "oiuas\tdfkj" 112 # v = test.isprintable() 113 # print(v) 114 115 # 15 判断是否全部是空格 116 # test = "" 117 # v = test.isspace() 118 # print(v) 119 120 # 16 判断是否是标题 121 # test = "Return True if all cased characters in S are uppercase and there is" 122 # v1 = test.istitle() 123 # print(v1) 124 # v2 = test.title() 125 # print(v2) 126 # v3 = v2.istitle() 127 # print(v3) 128 129 # 17 ***** 将字符串中的每一个元素按照指定分隔符进行拼接 130 # test = "你是风儿我是沙" 131 # print(test) 132 # # t = ' ' 133 # v = "_".join(test) 134 # print(v) 135 136 # 18 判断是否全部是大小写 和 转换为大小写 137 # test = "Alex" 138 # v1 = test.islower() 139 # v2 = test.lower() 140 # print(v1, v2) 141 142 # v1 = test.isupper() 143 # v2 = test.upper() 144 # print(v1,v2) 145 # 19 146 # 移除指定字符串 147 # 有限最多匹配 148 # test = "xa" 149 # # v = test.lstrip('xa') 150 # v = test.rstrip('9lexxexa') 151 # # v = test.strip('xa') 152 # print(v) 153 154 # test.lstrip() 155 # test.rstrip() 156 # test.strip() 157 # 去除左右空白 158 # v = test.lstrip() 159 # v = test.rstrip() 160 # v = test.strip() 161 # print(v) 162 # print(test) 163 # 去除\t \n 164 # v = test.lstrip() 165 # v = test.rstrip() 166 # v = test.strip() 167 # print(v) 168 169 # 20 对应关系替换 170 # test = "aeiou" 171 # test1 = "12345" 172 173 # v = "asidufkasd;fiuadkf;adfkjalsdjf" 174 # m = str.maketrans("aeiou", "12345") 175 # new_v = v.translate(m) 176 # print(new_v) 177 178 # 21 分割为三部分 179 # test = "testasdsddfg" 180 # v = test.partition('s') 181 # print(v) 182 # v = test.rpartition('s') 183 # print(v) 184 185 # 22 分割为指定个数 186 # v = test.split('s',2) 187 # print(v) 188 # test.rsplit() 189 190 191 # 23 分割,只能根据,true,false:是否保留换行 192 # test = "asdfadfasdf\nasdfasdf\nadfasdf" 193 # v = test.splitlines(False) 194 # print(v) 195 196 # 24 以xxx开头,以xx结尾 197 # test = "backend 1.1.1.1" 198 # v = test.startswith('a') 199 # print(v) 200 # test.endswith('a) 201 202 # 25 大小写转换 203 # test = "aLex" 204 # v = test.swapcase() 205 # print(v) 206 207 # 26 字母,数字,下划线 : 标识符 def class 208 # a = "def" 209 # v = a.isidentifier() 210 # print(v) 211 212 213 # 27 将指定字符串替换为指定字符串 214 # test = "alexalexalex" 215 # v = test.replace("ex",'bbb') 216 # print(v) 217 # v = test.replace("ex",'bbb',2) 218 # print(v) 219 ###################### 7个基本魔法 ###################### 220 # join # '_'.join("asdfasdf") 221 # split 222 # find 223 # strip 224 # upper 225 # lower 226 # replace 227 ###################### 4个灰魔法 ###################### 228 # test = "郑建文妹子有种冲我来" 229 230 # 一、for循环 231 # for 变量名 in 字符串: 232 # 变量名 233 # break 234 # continue 235 236 237 # index = 0 238 # while index < len(test): 239 # v = test[index] 240 # print(v) 241 # 242 # index += 1 243 # print('=======') 244 245 # for zjw in test: 246 # print(zjw) 247 248 # test = "郑建文妹子有种冲我来" 249 # for item in test: 250 # print(item) 251 # break 252 253 # for item in test: 254 # continue 255 # print(item) 256 257 # 二、索引,下标,获取字符串中的某一个字符 258 # v = test[3] 259 # print(v) 260 261 # 三、切片 262 # v = test[0:-1] # 0=< <1 263 # print(v) 264 265 # 四、获取长度 266 # Python3: len获取当前字符串中由几个字符组成 267 # v = len(test) 268 # print(v) 269 270 # 注意: 271 # len("asdf") 272 # for循环 273 # 索引 274 # 切片 275 276 # 五、获取连续或不连续的数字, 277 # Python2中直接创建在内容中 278 # python3中只有for循环时,才一个一个创建 279 # r1 = range(10) 280 # r2 = range(1,10) 281 # r3 = range(1,10,2) 282 # 帮助创建连续的数字,通过设置步长来指定不连续 283 # v = range(0, 100, 5) 284 # 285 # for item in v: 286 # print(item) 287 288 ##### 练习题:根据用户输入的值,输出每一个字符以及当前字符所在的索引位置 ##### 289 # test = input(">>>") 290 # for item in test: 291 # print(item) 292 293 # 将文字 对应的索引打印出来: 294 # test = input(">>>") 295 # print(test) # test = qwe test[0] test[1] 296 # l = len(test) # l = 3 297 # print(l) 298 # 299 # r = range(0,l) # 0,3 300 # for item in r: 301 # print(item, test[item]) # 0 q,1 w,2 e 302 303 # test = input(">>>") 304 # for item in range(0, len(test)): 305 # print(item, test[item]) 306 307 308 309 310 ###################### 1个深灰魔法 ###################### 311 # 字符串一旦创建,不可修改 312 # 一旦修改或者拼接,都会造成重新生成字符串 313 314 # name = "zhengjianwen" 315 # age = "18" 316 # 317 # info = name + age 318 # print(info)
万恶的字符串拼接:
python中的字符串在C语言中体现为是一个字符数组,每次创建字符串时候需要在内存中开辟一块连续的空,并且一旦需要修改字符串的话,就需要再次开辟空间,万恶的+号每出现一次就会在内从中重新开辟一块空间。
字符串格式化:
name = "alex" print "i am %s " % name #输出: i am alex
PS: 字符串是 %s;整数 %d;浮点数%f
字符串常用功能:- 移除空白 :strip
- 分割 :split
- 长度 :len()
- 索引 :find
- 切片 :test[0:-1]
- 添加 :'_'.join("asdfasdf")
- 变成大写 :upper
- 变成小写 :lower
- 替换 :replace
2、列表
列表是有序的,列表元素可以被修改
创建列表:
name_list = ['alex', 'seven', 'eric'] 或 name_list = list(['alex', 'seven', 'eric'])
每个列表都具备如下功能:

1 class list(object): 2 """ 3 list() -> new empty list 4 list(iterable) -> new list initialized from iterable's items 5 """ 6 def append(self, p_object): # real signature unknown; restored from __doc__ 7 """ L.append(object) -> None -- append object to end """ 8 pass 9 10 def clear(self): # real signature unknown; restored from __doc__ 11 """ L.clear() -> None -- remove all items from L """ 12 pass 13 14 def copy(self): # real signature unknown; restored from __doc__ 15 """ L.copy() -> list -- a shallow copy of L """ 16 return [] 17 18 def count(self, value): # real signature unknown; restored from __doc__ 19 """ L.count(value) -> integer -- return number of occurrences of value """ 20 return 0 21 22 def extend(self, iterable): # real signature unknown; restored from __doc__ 23 """ L.extend(iterable) -> None -- extend list by appending elements from the iterable """ 24 pass 25 26 def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__ 27 """ 28 L.index(value, [start, [stop]]) -> integer -- return first index of value. 29 Raises ValueError if the value is not present. 30 """ 31 return 0 32 33 def insert(self, index, p_object): # real signature unknown; restored from __doc__ 34 """ L.insert(index, object) -- insert object before index """ 35 pass 36 37 def pop(self, index=None): # real signature unknown; restored from __doc__ 38 """ 39 L.pop([index]) -> item -- remove and return item at index (default last). 40 Raises IndexError if list is empty or index is out of range. 41 """ 42 pass 43 44 def remove(self, value): # real signature unknown; restored from __doc__ 45 """ 46 L.remove(value) -> None -- remove first occurrence of value. 47 Raises ValueError if the value is not present. 48 """ 49 pass 50 51 def reverse(self): # real signature unknown; restored from __doc__ 52 """ L.reverse() -- reverse *IN PLACE* """ 53 pass 54 55 def sort(self, key=None, reverse=False): # real signature unknown; restored from __doc__ 56 """ L.sort(key=None, reverse=False) -> None -- stable sort *IN PLACE* """ 57 pass 58 59 def __add__(self, *args, **kwargs): # real signature unknown 60 """ Return self+value. """ 61 pass 62 63 def __contains__(self, *args, **kwargs): # real signature unknown 64 """ Return key in self. """ 65 pass 66 67 def __delitem__(self, *args, **kwargs): # real signature unknown 68 """ Delete self[key]. """ 69 pass 70 71 def __eq__(self, *args, **kwargs): # real signature unknown 72 """ Return self==value. """ 73 pass 74 75 def __getattribute__(self, *args, **kwargs): # real signature unknown 76 """ Return getattr(self, name). """ 77 pass 78 79 def __getitem__(self, y): # real signature unknown; restored from __doc__ 80 """ x.__getitem__(y) <==> x[y] """ 81 pass 82 83 def __ge__(self, *args, **kwargs): # real signature unknown 84 """ Return self>=value. """ 85 pass 86 87 def __gt__(self, *args, **kwargs): # real signature unknown 88 """ Return self>value. """ 89 pass 90 91 def __iadd__(self, *args, **kwargs): # real signature unknown 92 """ Implement self+=value. """ 93 pass 94 95 def __imul__(self, *args, **kwargs): # real signature unknown 96 """ Implement self*=value. """ 97 pass 98 99 def __init__(self, seq=()): # known special case of list.__init__ 100 """ 101 list() -> new empty list 102 list(iterable) -> new list initialized from iterable's items 103 # (copied from class doc) 104 """ 105 pass 106 107 def __iter__(self, *args, **kwargs): # real signature unknown 108 """ Implement iter(self). """ 109 pass 110 111 def __len__(self, *args, **kwargs): # real signature unknown 112 """ Return len(self). """ 113 pass 114 115 def __le__(self, *args, **kwargs): # real signature unknown 116 """ Return self<=value. """ 117 pass 118 119 def __lt__(self, *args, **kwargs): # real signature unknown 120 """ Return self<value. """ 121 pass 122 123 def __mul__(self, *args, **kwargs): # real signature unknown 124 """ Return self*value.n """ 125 pass 126 127 @staticmethod # known case of __new__ 128 def __new__(*args, **kwargs): # real signature unknown 129 """ Create and return a new object. See help(type) for accurate signature. """ 130 pass 131 132 def __ne__(self, *args, **kwargs): # real signature unknown 133 """ Return self!=value. """ 134 pass 135 136 def __repr__(self, *args, **kwargs): # real signature unknown 137 """ Return repr(self). """ 138 pass 139 140 def __reversed__(self): # real signature unknown; restored from __doc__ 141 """ L.__reversed__() -- return a reverse iterator over the list """ 142 pass 143 144 def __rmul__(self, *args, **kwargs): # real signature unknown 145 """ Return self*value. """ 146 pass 147 148 def __setitem__(self, *args, **kwargs): # real signature unknown 149 """ Set self[key] to value. """ 150 pass 151 152 def __sizeof__(self): # real signature unknown; restored from __doc__ 153 """ L.__sizeof__() -- size of L in memory, in bytes """ 154 pass 155 156 __hash__ = None

1 # 元组,元素不可被修改,不能被增加或者删除 2 # tuple 3 # tu = (11,22,33,44) 4 # tu.count(22),获取指定元素在元组中出现的次数 5 # tu.index(22) 6 7 ####################################### 深灰魔法 ####################################### 8 # 1. 书写格式 9 # tu = (111,"alex",(11,22),[(33,44)],True,33,44,) 10 # 一般写元组的时候,推荐在最后加入逗号 , 11 # 元素不可被修改,不能被增加或者删除 12 # 2. 索引 13 # v = tu[0] 14 # print(v) 15 16 # 3. 切片 17 # v = tu[0:2] 18 # print(v) 19 20 # 4. 可以被for循环,可迭代对象 21 # for item in tu: 22 # print(item) 23 24 # 5. 转换 25 # s = "asdfasdf0" 26 # li = ["asdf","asdfasdf"] 27 # tu = ("asdf","asdf") 28 # 29 # v = tuple(s) 30 # print(v) 31 32 # v = tuple(li) 33 # print(v) 34 35 # v = list(tu) 36 # print(v) 37 38 # v = "_".join(tu) 39 # print(v) 40 41 # li = ["asdf","asdfasdf"] 42 # li.extend((11,22,33,)) 43 # print(li) 44 45 # 6.元组的一级元素不可修改/删除/增加 46 # tu = (111,"alex",(11,22),[(33,44)],True,33,44,) 47 # # 元组,有序。 48 # # v = tu[3][0][0] 49 # # print(v) 50 # # v=tu[3] 51 # # print(v) 52 # tu[3][0] = 567 53 # print(tu)
基本操作:
- 索引:li[0]
- 切片:li[0:3]
- 循环:for
- 长度:len()
- 包含:in
- 添加:li.append() 原来值后面追加
- 清空列表:li.clear()
- 删除某个值:li.pop()(1.指定索引;2. 默认最后一个),并获取删除的值,remove()删除列表中的指定值,左边优先
- 将当前列表进行翻转 :li.reverse()
- 列表的排序 :li.sort()
- 计算元素出现的次数 :li.count(22)
- 拷贝,浅拷贝 :li.copy()
3、元祖
元组,元素不可被修改,不能被增加或者删除
创建元祖(注:最后应该加个逗号):
ages = (11, 22, 33, 44, 55,) 或 ages = tuple((11, 22, 33, 44, 55,))
每个元组都具备如下功能:

1 class tuple(object): 2 """ 3 tuple() -> empty tuple 4 tuple(iterable) -> tuple initialized from iterable's items 5 6 If the argument is a tuple, the return value is the same object. 7 """ 8 def count(self, value): # real signature unknown; restored from __doc__ 9 """ T.count(value) -> integer -- return number of occurrences of value """ 10 return 0 11 12 def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__ 13 """ 14 T.index(value, [start, [stop]]) -> integer -- return first index of value. 15 Raises ValueError if the value is not present. 16 """ 17 return 0 18 19 def __add__(self, y): # real signature unknown; restored from __doc__ 20 """ x.__add__(y) <==> x+y """ 21 pass 22 23 def __contains__(self, y): # real signature unknown; restored from __doc__ 24 """ x.__contains__(y) <==> y in x """ 25 pass 26 27 def __eq__(self, y): # real signature unknown; restored from __doc__ 28 """ x.__eq__(y) <==> x==y """ 29 pass 30 31 def __getattribute__(self, name): # real signature unknown; restored from __doc__ 32 """ x.__getattribute__('name') <==> x.name """ 33 pass 34 35 def __getitem__(self, y): # real signature unknown; restored from __doc__ 36 """ x.__getitem__(y) <==> x[y] """ 37 pass 38 39 def __getnewargs__(self, *args, **kwargs): # real signature unknown 40 pass 41 42 def __getslice__(self, i, j): # real signature unknown; restored from __doc__ 43 """ 44 x.__getslice__(i, j) <==> x[i:j] 45 46 Use of negative indices is not supported. 47 """ 48 pass 49 50 def __ge__(self, y): # real signature unknown; restored from __doc__ 51 """ x.__ge__(y) <==> x>=y """ 52 pass 53 54 def __gt__(self, y): # real signature unknown; restored from __doc__ 55 """ x.__gt__(y) <==> x>y """ 56 pass 57 58 def __hash__(self): # real signature unknown; restored from __doc__ 59 """ x.__hash__() <==> hash(x) """ 60 pass 61 62 def __init__(self, seq=()): # known special case of tuple.__init__ 63 """ 64 tuple() -> empty tuple 65 tuple(iterable) -> tuple initialized from iterable's items 66 67 If the argument is a tuple, the return value is the same object. 68 # (copied from class doc) 69 """ 70 pass 71 72 def __iter__(self): # real signature unknown; restored from __doc__ 73 """ x.__iter__() <==> iter(x) """ 74 pass 75 76 def __len__(self): # real signature unknown; restored from __doc__ 77 """ x.__len__() <==> len(x) """ 78 pass 79 80 def __le__(self, y): # real signature unknown; restored from __doc__ 81 """ x.__le__(y) <==> x<=y """ 82 pass 83 84 def __lt__(self, y): # real signature unknown; restored from __doc__ 85 """ x.__lt__(y) <==> x<y """ 86 pass 87 88 def __mul__(self, n): # real signature unknown; restored from __doc__ 89 """ x.__mul__(n) <==> x*n """ 90 pass 91 92 @staticmethod # known case of __new__ 93 def __new__(S, *more): # real signature unknown; restored from __doc__ 94 """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ 95 pass 96 97 def __ne__(self, y): # real signature unknown; restored from __doc__ 98 """ x.__ne__(y) <==> x!=y """ 99 pass 100 101 def __repr__(self): # real signature unknown; restored from __doc__ 102 """ x.__repr__() <==> repr(x) """ 103 pass 104 105 def __rmul__(self, n): # real signature unknown; restored from __doc__ 106 """ x.__rmul__(n) <==> n*x """ 107 pass 108 109 def __sizeof__(self): # real signature unknown; restored from __doc__ 110 """ T.__sizeof__() -- size of T in memory, in bytes """ 111 pass 112 113 tuple

1 # 元组,元素不可被修改,不能被增加或者删除 2 # tuple 3 # tu = (11,22,33,44) 4 # tu.count(22),获取指定元素在元组中出现的次数 5 # tu.index(22) 6 7 ####################################### 深灰魔法 ####################################### 8 # 1. 书写格式 9 # tu = (111,"alex",(11,22),[(33,44)],True,33,44,) 10 # 一般写元组的时候,推荐在最后加入 , 11 # 元素不可被修改,不能被增加或者删除 12 # 2. 索引 13 # v = tu[0] 14 # print(v) 15 16 # 3. 切片 17 # v = tu[0:2] 18 # print(v) 19 20 # 4. 可以被for循环,可迭代对象 21 # for item in tu: 22 # print(item) 23 24 # 5. 转换 25 # s = "asdfasdf0" 26 # li = ["asdf","asdfasdf"] 27 # tu = ("asdf","asdf") 28 # 29 # v = tuple(s) 30 # print(v) 31 32 # v = tuple(li) 33 # print(v) 34 35 # v = list(tu) 36 # print(v) 37 38 # v = "_".join(tu) 39 # print(v) 40 41 # li = ["asdf","asdfasdf"] 42 # li.extend((11,22,33,)) 43 # print(li) 44 45 # 6.元组的一级元素不可修改/删除/增加 46 # tu = (111,"alex",(11,22),[(33,44)],True,33,44,) 47 # # 元组,有序。 48 # # v = tu[3][0][0] 49 # # print(v) 50 # # v=tu[3] 51 # # print(v) 52 # tu[3][0] = 567 53 # print(tu)
基本操作:
- 索引
- 切片
- 循环
- 长度
- 包含
4、字典
字典,无序的
创建字典:
person = {"name": "mr.wu", 'age': 18} 或 person = dict({"name": "mr.wu", 'age': 18})
每个字典都具备如下功能:

1 class dict(object): 2 """ 3 dict() -> new empty dictionary 4 dict(mapping) -> new dictionary initialized from a mapping object's 5 (key, value) pairs 6 dict(iterable) -> new dictionary initialized as if via: 7 d = {} 8 for k, v in iterable: 9 d[k] = v 10 dict(**kwargs) -> new dictionary initialized with the name=value pairs 11 in the keyword argument list. For example: dict(one=1, two=2) 12 """ 13 14 def clear(self): # real signature unknown; restored from __doc__ 15 """ 清除内容 """ 16 """ D.clear() -> None. Remove all items from D. """ 17 pass 18 19 def copy(self): # real signature unknown; restored from __doc__ 20 """ 浅拷贝 """ 21 """ D.copy() -> a shallow copy of D """ 22 pass 23 24 @staticmethod # known case 25 def fromkeys(S, v=None): # real signature unknown; restored from __doc__ 26 """ 27 dict.fromkeys(S[,v]) -> New dict with keys from S and values equal to v. 28 v defaults to None. 29 """ 30 pass 31 32 def get(self, k, d=None): # real signature unknown; restored from __doc__ 33 """ 根据key获取值,d是默认值 """ 34 """ D.get(k[,d]) -> D[k] if k in D, else d. d defaults to None. """ 35 pass 36 37 def has_key(self, k): # real signature unknown; restored from __doc__ 38 """ 是否有key """ 39 """ D.has_key(k) -> True if D has a key k, else False """ 40 return False 41 42 def items(self): # real signature unknown; restored from __doc__ 43 """ 所有项的列表形式 """ 44 """ D.items() -> list of D's (key, value) pairs, as 2-tuples """ 45 return [] 46 47 def iteritems(self): # real signature unknown; restored from __doc__ 48 """ 项可迭代 """ 49 """ D.iteritems() -> an iterator over the (key, value) items of D """ 50 pass 51 52 def iterkeys(self): # real signature unknown; restored from __doc__ 53 """ key可迭代 """ 54 """ D.iterkeys() -> an iterator over the keys of D """ 55 pass 56 57 def itervalues(self): # real signature unknown; restored from __doc__ 58 """ value可迭代 """ 59 """ D.itervalues() -> an iterator over the values of D """ 60 pass 61 62 def keys(self): # real signature unknown; restored from __doc__ 63 """ 所有的key列表 """ 64 """ D.keys() -> list of D's keys """ 65 return [] 66 67 def pop(self, k, d=None): # real signature unknown; restored from __doc__ 68 """ 获取并在字典中移除 """ 69 """ 70 D.pop(k[,d]) -> v, remove specified key and return the corresponding value. 71 If key is not found, d is returned if given, otherwise KeyError is raised 72 """ 73 pass 74 75 def popitem(self): # real signature unknown; restored from __doc__ 76 """ 获取并在字典中移除 """ 77 """ 78 D.popitem() -> (k, v), remove and return some (key, value) pair as a 79 2-tuple; but raise KeyError if D is empty. 80 """ 81 pass 82 83 def setdefault(self, k, d=None): # real signature unknown; restored from __doc__ 84 """ 如果key不存在,则创建,如果存在,则返回已存在的值且不修改 """ 85 """ D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D """ 86 pass 87 88 def update(self, E=None, **F): # known special case of dict.update 89 """ 更新 90 {'name':'alex', 'age': 18000} 91 [('name','sbsbsb'),] 92 """ 93 """ 94 D.update([E, ]**F) -> None. Update D from dict/iterable E and F. 95 If E present and has a .keys() method, does: for k in E: D[k] = E[k] 96 If E present and lacks .keys() method, does: for (k, v) in E: D[k] = v 97 In either case, this is followed by: for k in F: D[k] = F[k] 98 """ 99 pass 100 101 def values(self): # real signature unknown; restored from __doc__ 102 """ 所有的值 """ 103 """ D.values() -> list of D's values """ 104 return [] 105 106 def viewitems(self): # real signature unknown; restored from __doc__ 107 """ 所有项,只是将内容保存至view对象中 """ 108 """ D.viewitems() -> a set-like object providing a view on D's items """ 109 pass 110 111 def viewkeys(self): # real signature unknown; restored from __doc__ 112 """ D.viewkeys() -> a set-like object providing a view on D's keys """ 113 pass 114 115 def viewvalues(self): # real signature unknown; restored from __doc__ 116 """ D.viewvalues() -> an object providing a view on D's values """ 117 pass 118 119 def __cmp__(self, y): # real signature unknown; restored from __doc__ 120 """ x.__cmp__(y) <==> cmp(x,y) """ 121 pass 122 123 def __contains__(self, k): # real signature unknown; restored from __doc__ 124 """ D.__contains__(k) -> True if D has a key k, else False """ 125 return False 126 127 def __delitem__(self, y): # real signature unknown; restored from __doc__ 128 """ x.__delitem__(y) <==> del x[y] """ 129 pass 130 131 def __eq__(self, y): # real signature unknown; restored from __doc__ 132 """ x.__eq__(y) <==> x==y """ 133 pass 134 135 def __getattribute__(self, name): # real signature unknown; restored from __doc__ 136 """ x.__getattribute__('name') <==> x.name """ 137 pass 138 139 def __getitem__(self, y): # real signature unknown; restored from __doc__ 140 """ x.__getitem__(y) <==> x[y] """ 141 pass 142 143 def __ge__(self, y): # real signature unknown; restored from __doc__ 144 """ x.__ge__(y) <==> x>=y """ 145 pass 146 147 def __gt__(self, y): # real signature unknown; restored from __doc__ 148 """ x.__gt__(y) <==> x>y """ 149 pass 150 151 def __init__(self, seq=None, **kwargs): # known special case of dict.__init__ 152 """ 153 dict() -> new empty dictionary 154 dict(mapping) -> new dictionary initialized from a mapping object's 155 (key, value) pairs 156 dict(iterable) -> new dictionary initialized as if via: 157 d = {} 158 for k, v in iterable: 159 d[k] = v 160 dict(**kwargs) -> new dictionary initialized with the name=value pairs 161 in the keyword argument list. For example: dict(one=1, two=2) 162 # (copied from class doc) 163 """ 164 pass 165 166 def __iter__(self): # real signature unknown; restored from __doc__ 167 """ x.__iter__() <==> iter(x) """ 168 pass 169 170 def __len__(self): # real signature unknown; restored from __doc__ 171 """ x.__len__() <==> len(x) """ 172 pass 173 174 def __le__(self, y): # real signature unknown; restored from __doc__ 175 """ x.__le__(y) <==> x<=y """ 176 pass 177 178 def __lt__(self, y): # real signature unknown; restored from __doc__ 179 """ x.__lt__(y) <==> x<y """ 180 pass 181 182 @staticmethod # known case of __new__ 183 def __new__(S, *more): # real signature unknown; restored from __doc__ 184 """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ 185 pass 186 187 def __ne__(self, y): # real signature unknown; restored from __doc__ 188 """ x.__ne__(y) <==> x!=y """ 189 pass 190 191 def __repr__(self): # real signature unknown; restored from __doc__ 192 """ x.__repr__() <==> repr(x) """ 193 pass 194 195 def __setitem__(self, i, y): # real signature unknown; restored from __doc__ 196 """ x.__setitem__(i, y) <==> x[i]=y """ 197 pass 198 199 def __sizeof__(self): # real signature unknown; restored from __doc__ 200 """ D.__sizeof__() -> size of D in memory, in bytes """ 201 pass 202 203 __hash__ = None 204 205 dict

1 # 字典 2 # dict 3 # dict 4 # dic = { 5 # "k1": 'v1', 6 # "k2": 'v2' 7 # } 8 # 1 根据序列,创建字典,并指定统一的值 9 # v = dict.fromkeys(["k1",123,"999"],123) 10 # print(v) 11 12 # 2 根据Key获取值,key不存在时,可以指定默认值(None) 13 # v = dic['k11111'] 14 # print(v) 15 # v = dic.get('k1',111111) 16 # print(v) 17 18 # 3 删除并获取值 19 # dic = { 20 # "k1": 'v1', 21 # "k2": 'v2' 22 # } 23 # v = dic.pop('k1',90) 24 # print(dic,v) 25 # k,v = dic.popitem() 26 # print(dic,k,v) 27 28 # 4 设置值, 29 # 已存在,不设置,获取当前key对应的值 30 # 不存在,设置,获取当前key对应的值 31 # dic = { 32 # "k1": 'v1', 33 # "k2": 'v2' 34 # } 35 # v = dic.setdefault('k1111','123') 36 # print(dic,v) 37 38 # 5 更新 39 # dic = { 40 # "k1": 'v1', 41 # "k2": 'v2' 42 # } 43 # dic.update({'k1': '111111','k3': 123}) 44 # print(dic) 45 # dic.update(k1=123,k3=345,k5="asdf") 46 # print(dic) 47 48 # 6 keys() 7 values() 8 items() get update 49 ########## 50 51 52 53 # 1、基本机构 54 # info = { 55 # "k1": "v1", # 键值对 56 # "k2": "v2" 57 # } 58 #### 2 字典的value可以是任何值 59 # info = { 60 # "k1": 18, 61 # "k2": True, 62 # "k3": [ 63 # 11, 64 # [], 65 # (), 66 # 22, 67 # 33, 68 # { 69 # 'kk1': 'vv1', 70 # 'kk2': 'vv2', 71 # 'kk3': (11,22), 72 # } 73 # ], 74 # "k4": (11,22,33,44) 75 # } 76 # print(info) 77 78 #### 3 布尔值(1,0)、列表、字典不能作为字典的key 79 # info ={ 80 # 1: 'asdf', 81 # "k1": 'asdf', 82 # True: "123", 83 # # [11,22]: 123 84 # (11,22): 123, 85 # # {'k1':'v1'}: 123 86 # 87 # } 88 # print(info) 89 90 # 4 字典无序 91 92 # info = { 93 # "k1": 18, 94 # "k2": True, 95 # "k3": [ 96 # 11, 97 # [], 98 # (), 99 # 22, 100 # 33, 101 # { 102 # 'kk1': 'vv1', 103 # 'kk2': 'vv2', 104 # 'kk3': (11,22), 105 # } 106 # ], 107 # "k4": (11,22,33,44) 108 # } 109 # print(info) 110 111 # 5、索引方式找到指定元素 112 # info = { 113 # "k1": 18, 114 # 2: True, 115 # "k3": [ 116 # 11, 117 # [], 118 # (), 119 # 22, 120 # 33, 121 # { 122 # 'kk1': 'vv1', 123 # 'kk2': 'vv2', 124 # 'kk3': (11,22), 125 # } 126 # ], 127 # "k4": (11,22,33,44) 128 # } 129 # # v = info['k1'] 130 # # print(v) 131 # # v = info[2] 132 # # print(v) 133 # v = info['k3'][5]['kk3'][0] 134 # print(v) 135 136 # 6 字典支持 del 删除 137 # info = { 138 # "k1": 18, 139 # 2: True, 140 # "k3": [ 141 # 11, 142 # [], 143 # (), 144 # 22, 145 # 33, 146 # { 147 # 'kk1': 'vv1', 148 # 'kk2': 'vv2', 149 # 'kk3': (11,22), 150 # } 151 # ], 152 # "k4": (11,22,33,44) 153 # } 154 # del info['k1'] 155 # 156 # del info['k3'][5]['kk1'] 157 # print(info) 158 159 # 7 for循环 160 # dict 161 # info = { 162 # "k1": 18, 163 # 2: True, 164 # "k3": [ 165 # 11, 166 # [], 167 # (), 168 # 22, 169 # 33, 170 # { 171 # 'kk1': 'vv1', 172 # 'kk2': 'vv2', 173 # 'kk3': (11,22), 174 # } 175 # ], 176 # "k4": (11,22,33,44) 177 # } 178 # for item in info: 179 # print(item) 180 # 181 # for item in info.keys(): 182 # print(item) 183 184 # for item in info.values(): 185 # print(item) 186 187 # for item in info.keys(): 188 # print(item,info[item]) 189 190 # for k,v in info.items(): 191 # print(k,v) 192 193 # True 1 False 0 194 # info ={ 195 # "k1": 'asdf', 196 # True: "123", 197 # # [11,22]: 123 198 # (11,22): 123, 199 # # {'k1':' v1'}: 123 200 # 201 # } 202 # print(info)
常用操作:
- 索引
- 新增
- 删除
- 键、值、键值对
- 循环
- 长度
PS:循环,range,continue 和 break
八、set集合
set是一个无序且不重复的元素集合

1 class set(object): 2 """ 3 set() -> new empty set object 4 set(iterable) -> new set object 5 6 Build an unordered collection of unique elements. 7 """ 8 def add(self, *args, **kwargs): # real signature unknown 9 """ 添加 """ 10 """ 11 Add an element to a set. 12 13 This has no effect if the element is already present. 14 """ 15 pass 16 17 def clear(self, *args, **kwargs): # real signature unknown 18 """ Remove all elements from this set. """ 19 pass 20 21 def copy(self, *args, **kwargs): # real signature unknown 22 """ Return a shallow copy of a set. """ 23 pass 24 25 def difference(self, *args, **kwargs): # real signature unknown 26 """ 27 Return the difference of two or more sets as a new set. 28 29 (i.e. all elements that are in this set but not the others.) 30 """ 31 pass 32 33 def difference_update(self, *args, **kwargs): # real signature unknown 34 """ 删除当前set中的所有包含在 new set 里的元素 """ 35 """ Remove all elements of another set from this set. """ 36 pass 37 38 def discard(self, *args, **kwargs): # real signature unknown 39 """ 移除元素 """ 40 """ 41 Remove an element from a set if it is a member. 42 43 If the element is not a member, do nothing. 44 """ 45 pass 46 47 def intersection(self, *args, **kwargs): # real signature unknown 48 """ 取交集,新创建一个set """ 49 """ 50 Return the intersection of two or more sets as a new set. 51 52 (i.e. elements that are common to all of the sets.) 53 """ 54 pass 55 56 def intersection_update(self, *args, **kwargs): # real signature unknown 57 """ 取交集,修改原来set """ 58 """ Update a set with the intersection of itself and another. """ 59 pass 60 61 def isdisjoint(self, *args, **kwargs): # real signature unknown 62 """ 如果没有交集,返回true """ 63 """ Return True if two sets have a null intersection. """ 64 pass 65 66 def issubset(self, *args, **kwargs): # real signature unknown 67 """ 是否是子集 """ 68 """ Report whether another set contains this set. """ 69 pass 70 71 def issuperset(self, *args, **kwargs): # real signature unknown 72 """ 是否是父集 """ 73 """ Report whether this set contains another set. """ 74 pass 75 76 def pop(self, *args, **kwargs): # real signature unknown 77 """ 移除 """ 78 """ 79 Remove and return an arbitrary set element. 80 Raises KeyError if the set is empty. 81 """ 82 pass 83 84 def remove(self, *args, **kwargs): # real signature unknown 85 """ 移除 """ 86 """ 87 Remove an element from a set; it must be a member. 88 89 If the element is not a member, raise a KeyError. 90 """ 91 pass 92 93 def symmetric_difference(self, *args, **kwargs): # real signature unknown 94 """ 差集,创建新对象""" 95 """ 96 Return the symmetric difference of two sets as a new set. 97 98 (i.e. all elements that are in exactly one of the sets.) 99 """ 100 pass 101 102 def symmetric_difference_update(self, *args, **kwargs): # real signature unknown 103 """ 差集,改变原来 """ 104 """ Update a set with the symmetric difference of itself and another. """ 105 pass 106 107 def union(self, *args, **kwargs): # real signature unknown 108 """ 并集 """ 109 """ 110 Return the union of sets as a new set. 111 112 (i.e. all elements that are in either set.) 113 """ 114 pass 115 116 def update(self, *args, **kwargs): # real signature unknown 117 """ 更新 """ 118 """ Update a set with the union of itself and others. """ 119 pass 120 121 def __and__(self, y): # real signature unknown; restored from __doc__ 122 """ x.__and__(y) <==> x&y """ 123 pass 124 125 def __cmp__(self, y): # real signature unknown; restored from __doc__ 126 """ x.__cmp__(y) <==> cmp(x,y) """ 127 pass 128 129 def __contains__(self, y): # real signature unknown; restored from __doc__ 130 """ x.__contains__(y) <==> y in x. """ 131 pass 132 133 def __eq__(self, y): # real signature unknown; restored from __doc__ 134 """ x.__eq__(y) <==> x==y """ 135 pass 136 137 def __getattribute__(self, name): # real signature unknown; restored from __doc__ 138 """ x.__getattribute__('name') <==> x.name """ 139 pass 140 141 def __ge__(self, y): # real signature unknown; restored from __doc__ 142 """ x.__ge__(y) <==> x>=y """ 143 pass 144 145 def __gt__(self, y): # real signature unknown; restored from __doc__ 146 """ x.__gt__(y) <==> x>y """ 147 pass 148 149 def __iand__(self, y): # real signature unknown; restored from __doc__ 150 """ x.__iand__(y) <==> x&=y """ 151 pass 152 153 def __init__(self, seq=()): # known special case of set.__init__ 154 """ 155 set() -> new empty set object 156 set(iterable) -> new set object 157 158 Build an unordered collection of unique elements. 159 # (copied from class doc) 160 """ 161 pass 162 163 def __ior__(self, y): # real signature unknown; restored from __doc__ 164 """ x.__ior__(y) <==> x|=y """ 165 pass 166 167 def __isub__(self, y): # real signature unknown; restored from __doc__ 168 """ x.__isub__(y) <==> x-=y """ 169 pass 170 171 def __iter__(self): # real signature unknown; restored from __doc__ 172 """ x.__iter__() <==> iter(x) """ 173 pass 174 175 def __ixor__(self, y): # real signature unknown; restored from __doc__ 176 """ x.__ixor__(y) <==> x^=y """ 177 pass 178 179 def __len__(self): # real signature unknown; restored from __doc__ 180 """ x.__len__() <==> len(x) """ 181 pass 182 183 def __le__(self, y): # real signature unknown; restored from __doc__ 184 """ x.__le__(y) <==> x<=y """ 185 pass 186 187 def __lt__(self, y): # real signature unknown; restored from __doc__ 188 """ x.__lt__(y) <==> x<y """ 189 pass 190 191 @staticmethod # known case of __new__ 192 def __new__(S, *more): # real signature unknown; restored from __doc__ 193 """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ 194 pass 195 196 def __ne__(self, y): # real signature unknown; restored from __doc__ 197 """ x.__ne__(y) <==> x!=y """ 198 pass 199 200 def __or__(self, y): # real signature unknown; restored from __doc__ 201 """ x.__or__(y) <==> x|y """ 202 pass 203 204 def __rand__(self, y): # real signature unknown; restored from __doc__ 205 """ x.__rand__(y) <==> y&x """ 206 pass 207 208 def __reduce__(self, *args, **kwargs): # real signature unknown 209 """ Return state information for pickling. """ 210 pass 211 212 def __repr__(self): # real signature unknown; restored from __doc__ 213 """ x.__repr__() <==> repr(x) """ 214 pass 215 216 def __ror__(self, y): # real signature unknown; restored from __doc__ 217 """ x.__ror__(y) <==> y|x """ 218 pass 219 220 def __rsub__(self, y): # real signature unknown; restored from __doc__ 221 """ x.__rsub__(y) <==> y-x """ 222 pass 223 224 def __rxor__(self, y): # real signature unknown; restored from __doc__ 225 """ x.__rxor__(y) <==> y^x """ 226 pass 227 228 def __sizeof__(self): # real signature unknown; restored from __doc__ 229 """ S.__sizeof__() -> size of S in memory, in bytes """ 230 pass 231 232 def __sub__(self, y): # real signature unknown; restored from __doc__ 233 """ x.__sub__(y) <==> x-y """ 234 pass 235 236 def __xor__(self, y): # real signature unknown; restored from __doc__ 237 """ x.__xor__(y) <==> x^y """ 238 pass 239 240 __hash__ = None 241 242 set
1 练习:寻找差异 2 # 数据库中原有 3 old_dict = { 4 "#1":{ 'hostname':c1, 'cpu_count': 2, 'mem_capicity': 80 }, 5 "#2":{ 'hostname':c1, 'cpu_count': 2, 'mem_capicity': 80 } 6 "#3":{ 'hostname':c1, 'cpu_count': 2, 'mem_capicity': 80 } 7 } 8 9 # cmdb 新汇报的数据 10 new_dict = { 11 "#1":{ 'hostname':c1, 'cpu_count': 2, 'mem_capicity': 800 }, 12 "#3":{ 'hostname':c1, 'cpu_count': 2, 'mem_capicity': 80 } 13 "#4":{ 'hostname':c2, 'cpu_count': 2, 'mem_capicity': 80 } 14 } 15 16 需要删除:? 17 需要新建:? 18 需要更新:? 注意:无需考虑内部元素是否改变,只要原来存在,新汇报也存在,就是需要更新

1 old_set = set(old_dict.keys()) 2 update_list = list(old_set.intersection(new_dict.keys())) 3 4 new_list = [] 5 del_list = [] 6 7 for i in new_dict.keys(): 8 if i not in update_list: 9 new_list.append(i) 10 11 for i in old_dict.keys(): 12 if i not in update_list: 13 del_list.append(i) 14 15 print update_list,new_list,del_list 16 17 demo
九、collection系列
1、计数器(counter)
Counter是对字典类型的补充,用于追踪值的出现次数。
ps:具备字典的所有功能 + 自己的功能
c = Counter('abcdeabcdabcaba') print c 输出:Counter({'a': 5, 'b': 4, 'c': 3, 'd': 2, 'e': 1})

1 ######################################################################## 2 ### Counter 3 ######################################################################## 4 5 class Counter(dict): 6 '''Dict subclass for counting hashable items. Sometimes called a bag 7 or multiset. Elements are stored as dictionary keys and their counts 8 are stored as dictionary values. 9 10 >>> c = Counter('abcdeabcdabcaba') # count elements from a string 11 12 >>> c.most_common(3) # three most common elements 13 [('a', 5), ('b', 4), ('c', 3)] 14 >>> sorted(c) # list all unique elements 15 ['a', 'b', 'c', 'd', 'e'] 16 >>> ''.join(sorted(c.elements())) # list elements with repetitions 17 'aaaaabbbbcccdde' 18 >>> sum(c.values()) # total of all counts 19 20 >>> c['a'] # count of letter 'a' 21 >>> for elem in 'shazam': # update counts from an iterable 22 ... c[elem] += 1 # by adding 1 to each element's count 23 >>> c['a'] # now there are seven 'a' 24 >>> del c['b'] # remove all 'b' 25 >>> c['b'] # now there are zero 'b' 26 27 >>> d = Counter('simsalabim') # make another counter 28 >>> c.update(d) # add in the second counter 29 >>> c['a'] # now there are nine 'a' 30 31 >>> c.clear() # empty the counter 32 >>> c 33 Counter() 34 35 Note: If a count is set to zero or reduced to zero, it will remain 36 in the counter until the entry is deleted or the counter is cleared: 37 38 >>> c = Counter('aaabbc') 39 >>> c['b'] -= 2 # reduce the count of 'b' by two 40 >>> c.most_common() # 'b' is still in, but its count is zero 41 [('a', 3), ('c', 1), ('b', 0)] 42 43 ''' 44 # References: 45 # http://en.wikipedia.org/wiki/Multiset 46 # http://www.gnu.org/software/smalltalk/manual-base/html_node/Bag.html 47 # http://www.demo2s.com/Tutorial/Cpp/0380__set-multiset/Catalog0380__set-multiset.htm 48 # http://code.activestate.com/recipes/259174/ 49 # Knuth, TAOCP Vol. II section 4.6.3 50 51 def __init__(self, iterable=None, **kwds): 52 '''Create a new, empty Counter object. And if given, count elements 53 from an input iterable. Or, initialize the count from another mapping 54 of elements to their counts. 55 56 >>> c = Counter() # a new, empty counter 57 >>> c = Counter('gallahad') # a new counter from an iterable 58 >>> c = Counter({'a': 4, 'b': 2}) # a new counter from a mapping 59 >>> c = Counter(a=4, b=2) # a new counter from keyword args 60 61 ''' 62 super(Counter, self).__init__() 63 self.update(iterable, **kwds) 64 65 def __missing__(self, key): 66 """ 对于不存在的元素,返回计数器为0 """ 67 'The count of elements not in the Counter is zero.' 68 # Needed so that self[missing_item] does not raise KeyError 69 return 0 70 71 def most_common(self, n=None): 72 """ 数量从大到写排列,获取前N个元素 """ 73 '''List the n most common elements and their counts from the most 74 common to the least. If n is None, then list all element counts. 75 76 >>> Counter('abcdeabcdabcaba').most_common(3) 77 [('a', 5), ('b', 4), ('c', 3)] 78 79 ''' 80 # Emulate Bag.sortedByCount from Smalltalk 81 if n is None: 82 return sorted(self.iteritems(), key=_itemgetter(1), reverse=True) 83 return _heapq.nlargest(n, self.iteritems(), key=_itemgetter(1)) 84 85 def elements(self): 86 """ 计数器中的所有元素,注:此处非所有元素集合,而是包含所有元素集合的迭代器 """ 87 '''Iterator over elements repeating each as many times as its count. 88 89 >>> c = Counter('ABCABC') 90 >>> sorted(c.elements()) 91 ['A', 'A', 'B', 'B', 'C', 'C'] 92 93 # Knuth's example for prime factors of 1836: 2**2 * 3**3 * 17**1 94 >>> prime_factors = Counter({2: 2, 3: 3, 17: 1}) 95 >>> product = 1 96 >>> for factor in prime_factors.elements(): # loop over factors 97 ... product *= factor # and multiply them 98 >>> product 99 100 Note, if an element's count has been set to zero or is a negative 101 number, elements() will ignore it. 102 103 ''' 104 # Emulate Bag.do from Smalltalk and Multiset.begin from C++. 105 return _chain.from_iterable(_starmap(_repeat, self.iteritems())) 106 107 # Override dict methods where necessary 108 109 @classmethod 110 def fromkeys(cls, iterable, v=None): 111 # There is no equivalent method for counters because setting v=1 112 # means that no element can have a count greater than one. 113 raise NotImplementedError( 114 'Counter.fromkeys() is undefined. Use Counter(iterable) instead.') 115 116 def update(self, iterable=None, **kwds): 117 """ 更新计数器,其实就是增加;如果原来没有,则新建,如果有则加一 """ 118 '''Like dict.update() but add counts instead of replacing them. 119 120 Source can be an iterable, a dictionary, or another Counter instance. 121 122 >>> c = Counter('which') 123 >>> c.update('witch') # add elements from another iterable 124 >>> d = Counter('watch') 125 >>> c.update(d) # add elements from another counter 126 >>> c['h'] # four 'h' in which, witch, and watch 127 128 ''' 129 # The regular dict.update() operation makes no sense here because the 130 # replace behavior results in the some of original untouched counts 131 # being mixed-in with all of the other counts for a mismash that 132 # doesn't have a straight-forward interpretation in most counting 133 # contexts. Instead, we implement straight-addition. Both the inputs 134 # and outputs are allowed to contain zero and negative counts. 135 136 if iterable is not None: 137 if isinstance(iterable, Mapping): 138 if self: 139 self_get = self.get 140 for elem, count in iterable.iteritems(): 141 self[elem] = self_get(elem, 0) + count 142 else: 143 super(Counter, self).update(iterable) # fast path when counter is empty 144 else: 145 self_get = self.get 146 for elem in iterable: 147 self[elem] = self_get(elem, 0) + 1 148 if kwds: 149 self.update(kwds) 150 151 def subtract(self, iterable=None, **kwds): 152 """ 相减,原来的计数器中的每一个元素的数量减去后添加的元素的数量 """ 153 '''Like dict.update() but subtracts counts instead of replacing them. 154 Counts can be reduced below zero. Both the inputs and outputs are 155 allowed to contain zero and negative counts. 156 157 Source can be an iterable, a dictionary, or another Counter instance. 158 159 >>> c = Counter('which') 160 >>> c.subtract('witch') # subtract elements from another iterable 161 >>> c.subtract(Counter('watch')) # subtract elements from another counter 162 >>> c['h'] # 2 in which, minus 1 in witch, minus 1 in watch 163 >>> c['w'] # 1 in which, minus 1 in witch, minus 1 in watch 164 -1 165 166 ''' 167 if iterable is not None: 168 self_get = self.get 169 if isinstance(iterable, Mapping): 170 for elem, count in iterable.items(): 171 self[elem] = self_get(elem, 0) - count 172 else: 173 for elem in iterable: 174 self[elem] = self_get(elem, 0) - 1 175 if kwds: 176 self.subtract(kwds) 177 178 def copy(self): 179 """ 拷贝 """ 180 'Return a shallow copy.' 181 return self.__class__(self) 182 183 def __reduce__(self): 184 """ 返回一个元组(类型,元组) """ 185 return self.__class__, (dict(self),) 186 187 def __delitem__(self, elem): 188 """ 删除元素 """ 189 'Like dict.__delitem__() but does not raise KeyError for missing values.' 190 if elem in self: 191 super(Counter, self).__delitem__(elem) 192 193 def __repr__(self): 194 if not self: 195 return '%s()' % self.__class__.__name__ 196 items = ', '.join(map('%r: %r'.__mod__, self.most_common())) 197 return '%s({%s})' % (self.__class__.__name__, items) 198 199 # Multiset-style mathematical operations discussed in: 200 # Knuth TAOCP Volume II section 4.6.3 exercise 19 201 # and at http://en.wikipedia.org/wiki/Multiset 202 # 203 # Outputs guaranteed to only include positive counts. 204 # 205 # To strip negative and zero counts, add-in an empty counter: 206 # c += Counter() 207 208 def __add__(self, other): 209 '''Add counts from two counters. 210 211 >>> Counter('abbb') + Counter('bcc') 212 Counter({'b': 4, 'c': 2, 'a': 1}) 213 214 ''' 215 if not isinstance(other, Counter): 216 return NotImplemented 217 result = Counter() 218 for elem, count in self.items(): 219 newcount = count + other[elem] 220 if newcount > 0: 221 result[elem] = newcount 222 for elem, count in other.items(): 223 if elem not in self and count > 0: 224 result[elem] = count 225 return result 226 227 def __sub__(self, other): 228 ''' Subtract count, but keep only results with positive counts. 229 230 >>> Counter('abbbc') - Counter('bccd') 231 Counter({'b': 2, 'a': 1}) 232 233 ''' 234 if not isinstance(other, Counter): 235 return NotImplemented 236 result = Counter() 237 for elem, count in self.items(): 238 newcount = count - other[elem] 239 if newcount > 0: 240 result[elem] = newcount 241 for elem, count in other.items(): 242 if elem not in self and count < 0: 243 result[elem] = 0 - count 244 return result 245 246 def __or__(self, other): 247 '''Union is the maximum of value in either of the input counters. 248 249 >>> Counter('abbb') | Counter('bcc') 250 Counter({'b': 3, 'c': 2, 'a': 1}) 251 252 ''' 253 if not isinstance(other, Counter): 254 return NotImplemented 255 result = Counter() 256 for elem, count in self.items(): 257 other_count = other[elem] 258 newcount = other_count if count < other_count else count 259 if newcount > 0: 260 result[elem] = newcount 261 for elem, count in other.items(): 262 if elem not in self and count > 0: 263 result[elem] = count 264 return result 265 266 def __and__(self, other): 267 ''' Intersection is the minimum of corresponding counts. 268 269 >>> Counter('abbb') & Counter('bcc') 270 Counter({'b': 1}) 271 272 ''' 273 if not isinstance(other, Counter): 274 return NotImplemented 275 result = Counter() 276 for elem, count in self.items(): 277 other_count = other[elem] 278 newcount = count if count < other_count else other_count 279 if newcount > 0: 280 result[elem] = newcount 281 return result 282 283 Counter
2、有序字典(orderedDict )
orderdDict是对字典类型的补充,他记住了字典元素添加的顺序

1 class OrderedDict(dict): 2 'Dictionary that remembers insertion order' 3 # An inherited dict maps keys to values. 4 # The inherited dict provides __getitem__, __len__, __contains__, and get. 5 # The remaining methods are order-aware. 6 # Big-O running times for all methods are the same as regular dictionaries. 7 8 # The internal self.__map dict maps keys to links in a doubly linked list. 9 # The circular doubly linked list starts and ends with a sentinel element. 10 # The sentinel element never gets deleted (this simplifies the algorithm). 11 # Each link is stored as a list of length three: [PREV, NEXT, KEY]. 12 13 def __init__(self, *args, **kwds): 14 '''Initialize an ordered dictionary. The signature is the same as 15 regular dictionaries, but keyword arguments are not recommended because 16 their insertion order is arbitrary. 17 18 ''' 19 if len(args) > 1: 20 raise TypeError('expected at most 1 arguments, got %d' % len(args)) 21 try: 22 self.__root 23 except AttributeError: 24 self.__root = root = [] # sentinel node 25 root[:] = [root, root, None] 26 self.__map = {} 27 self.__update(*args, **kwds) 28 29 def __setitem__(self, key, value, dict_setitem=dict.__setitem__): 30 'od.__setitem__(i, y) <==> od[i]=y' 31 # Setting a new item creates a new link at the end of the linked list, 32 # and the inherited dictionary is updated with the new key/value pair. 33 if key not in self: 34 root = self.__root 35 last = root[0] 36 last[1] = root[0] = self.__map[key] = [last, root, key] 37 return dict_setitem(self, key, value) 38 39 def __delitem__(self, key, dict_delitem=dict.__delitem__): 40 'od.__delitem__(y) <==> del od[y]' 41 # Deleting an existing item uses self.__map to find the link which gets 42 # removed by updating the links in the predecessor and successor nodes. 43 dict_delitem(self, key) 44 link_prev, link_next, _ = self.__map.pop(key) 45 link_prev[1] = link_next # update link_prev[NEXT] 46 link_next[0] = link_prev # update link_next[PREV] 47 48 def __iter__(self): 49 'od.__iter__() <==> iter(od)' 50 # Traverse the linked list in order. 51 root = self.__root 52 curr = root[1] # start at the first node 53 while curr is not root: 54 yield curr[2] # yield the curr[KEY] 55 curr = curr[1] # move to next node 56 57 def __reversed__(self): 58 'od.__reversed__() <==> reversed(od)' 59 # Traverse the linked list in reverse order. 60 root = self.__root 61 curr = root[0] # start at the last node 62 while curr is not root: 63 yield curr[2] # yield the curr[KEY] 64 curr = curr[0] # move to previous node 65 66 def clear(self): 67 'od.clear() -> None. Remove all items from od.' 68 root = self.__root 69 root[:] = [root, root, None] 70 self.__map.clear() 71 dict.clear(self) 72 73 # -- the following methods do not depend on the internal structure -- 74 75 def keys(self): 76 'od.keys() -> list of keys in od' 77 return list(self) 78 79 def values(self): 80 'od.values() -> list of values in od' 81 return [self[key] for key in self] 82 83 def items(self): 84 'od.items() -> list of (key, value) pairs in od' 85 return [(key, self[key]) for key in self] 86 87 def iterkeys(self): 88 'od.iterkeys() -> an iterator over the keys in od' 89 return iter(self) 90 91 def itervalues(self): 92 'od.itervalues -> an iterator over the values in od' 93 for k in self: 94 yield self[k] 95 96 def iteritems(self): 97 'od.iteritems -> an iterator over the (key, value) pairs in od' 98 for k in self: 99 yield (k, self[k]) 100 101 update = MutableMapping.update 102 103 __update = update # let subclasses override update without breaking __init__ 104 105 __marker = object() 106 107 def pop(self, key, default=__marker): 108 '''od.pop(k[,d]) -> v, remove specified key and return the corresponding 109 value. If key is not found, d is returned if given, otherwise KeyError 110 is raised. 111 112 ''' 113 if key in self: 114 result = self[key] 115 del self[key] 116 return result 117 if default is self.__marker: 118 raise KeyError(key) 119 return default 120 121 def setdefault(self, key, default=None): 122 'od.setdefault(k[,d]) -> od.get(k,d), also set od[k]=d if k not in od' 123 if key in self: 124 return self[key] 125 self[key] = default 126 return default 127 128 def popitem(self, last=True): 129 '''od.popitem() -> (k, v), return and remove a (key, value) pair. 130 Pairs are returned in LIFO order if last is true or FIFO order if false. 131 132 ''' 133 if not self: 134 raise KeyError('dictionary is empty') 135 key = next(reversed(self) if last else iter(self)) 136 value = self.pop(key) 137 return key, value 138 139 def __repr__(self, _repr_running={}): 140 'od.__repr__() <==> repr(od)' 141 call_key = id(self), _get_ident() 142 if call_key in _repr_running: 143 return '...' 144 _repr_running[call_key] = 1 145 try: 146 if not self: 147 return '%s()' % (self.__class__.__name__,) 148 return '%s(%r)' % (self.__class__.__name__, self.items()) 149 finally: 150 del _repr_running[call_key] 151 152 def __reduce__(self): 153 'Return state information for pickling' 154 items = [[k, self[k]] for k in self] 155 inst_dict = vars(self).copy() 156 for k in vars(OrderedDict()): 157 inst_dict.pop(k, None) 158 if inst_dict: 159 return (self.__class__, (items,), inst_dict) 160 return self.__class__, (items,) 161 162 def copy(self): 163 'od.copy() -> a shallow copy of od' 164 return self.__class__(self) 165 166 @classmethod 167 def fromkeys(cls, iterable, value=None): 168 '''OD.fromkeys(S[, v]) -> New ordered dictionary with keys from S. 169 If not specified, the value defaults to None. 170 171 ''' 172 self = cls() 173 for key in iterable: 174 self[key] = value 175 return self 176 177 def __eq__(self, other): 178 '''od.__eq__(y) <==> od==y. Comparison to another OD is order-sensitive 179 while comparison to a regular mapping is order-insensitive. 180 181 ''' 182 if isinstance(other, OrderedDict): 183 return dict.__eq__(self, other) and all(_imap(_eq, self, other)) 184 return dict.__eq__(self, other) 185 186 def __ne__(self, other): 187 'od.__ne__(y) <==> od!=y' 188 return not self == other 189 190 # -- the following methods support python 3.x style dictionary views -- 191 192 def viewkeys(self): 193 "od.viewkeys() -> a set-like object providing a view on od's keys" 194 return KeysView(self) 195 196 def viewvalues(self): 197 "od.viewvalues() -> an object providing a view on od's values" 198 return ValuesView(self) 199 200 def viewitems(self): 201 "od.viewitems() -> a set-like object providing a view on od's items" 202 return ItemsView(self) 203 204 OrderedDict
3、默认字典(defaultdict)
学前需求:
1 有如下值集合 [11,22,33,44,55,66,77,88,99,90...],将所有大于 66 的值保存至字典的第一个key中,将小于 66 的值保存至第二个key的值中。 2 即: {'k1': 大于66 , 'k2': 小于66}

values = [11, 22, 33,44,55,66,77,88,99,90] my_dict = {} for value in values: if value>66: if my_dict.has_key('k1'): my_dict['k1'].append(value) else: my_dict['k1'] = [value] else: if my_dict.has_key('k2'): my_dict['k2'].append(value) else: my_dict['k2'] = [value] 原生字典解决方法

1 from collections import defaultdict 2 3 values = [11, 22, 33,44,55,66,77,88,99,90] 4 5 my_dict = defaultdict(list) 6 7 for value in values: 8 if value>66: 9 my_dict['k1'].append(value) 10 else: 11 my_dict['k2'].append(value) 12 13 defaultdict字典解决方法
defaultdict是对字典的类型的补充,他默认给字典的值设置了一个类型。

1 class defaultdict(dict): 2 """ 3 defaultdict(default_factory[, ...]) --> dict with default factory 4 5 The default factory is called without arguments to produce 6 a new value when a key is not present, in __getitem__ only. 7 A defaultdict compares equal to a dict with the same items. 8 All remaining arguments are treated the same as if they were 9 passed to the dict constructor, including keyword arguments. 10 """ 11 def copy(self): # real signature unknown; restored from __doc__ 12 """ D.copy() -> a shallow copy of D. """ 13 pass 14 15 def __copy__(self, *args, **kwargs): # real signature unknown 16 """ D.copy() -> a shallow copy of D. """ 17 pass 18 19 def __getattribute__(self, name): # real signature unknown; restored from __doc__ 20 """ x.__getattribute__('name') <==> x.name """ 21 pass 22 23 def __init__(self, default_factory=None, **kwargs): # known case of _collections.defaultdict.__init__ 24 """ 25 defaultdict(default_factory[, ...]) --> dict with default factory 26 27 The default factory is called without arguments to produce 28 a new value when a key is not present, in __getitem__ only. 29 A defaultdict compares equal to a dict with the same items. 30 All remaining arguments are treated the same as if they were 31 passed to the dict constructor, including keyword arguments. 32 33 # (copied from class doc) 34 """ 35 pass 36 37 def __missing__(self, key): # real signature unknown; restored from __doc__ 38 """ 39 __missing__(key) # Called by __getitem__ for missing key; pseudo-code: 40 if self.default_factory is None: raise KeyError((key,)) 41 self[key] = value = self.default_factory() 42 return value 43 """ 44 pass 45 46 def __reduce__(self, *args, **kwargs): # real signature unknown 47 """ Return state information for pickling. """ 48 pass 49 50 def __repr__(self): # real signature unknown; restored from __doc__ 51 """ x.__repr__() <==> repr(x) """ 52 pass 53 54 default_factory = property(lambda self: object(), lambda self, v: None, lambda self: None) # default 55 """Factory for default value called by __missing__().""" 56 57 defaultdict
4、可命名元组(namedtuple)
根据nametuple可以创建一个包含tuple所有功能以及其他功能的类型。
1 import collections 2 3 Mytuple = collections.namedtuple('Mytuple',['x', 'y', 'z'])

1 class Mytuple(__builtin__.tuple) 2 | Mytuple(x, y) 3 | 4 | Method resolution order: 5 | Mytuple 6 | __builtin__.tuple 7 | __builtin__.object 8 | 9 | Methods defined here: 10 | 11 | __getnewargs__(self) 12 | Return self as a plain tuple. Used by copy and pickle. 13 | 14 | __getstate__(self) 15 | Exclude the OrderedDict from pickling 16 | 17 | __repr__(self) 18 | Return a nicely formatted representation string 19 | 20 | _asdict(self) 21 | Return a new OrderedDict which maps field names to their values 22 | 23 | _replace(_self, **kwds) 24 | Return a new Mytuple object replacing specified fields with new values 25 | 26 | ---------------------------------------------------------------------- 27 | Class methods defined here: 28 | 29 | _make(cls, iterable, new=<built-in method __new__ of type object>, len=<built-in function len>) from __builtin__.type 30 | Make a new Mytuple object from a sequence or iterable 31 | 32 | ---------------------------------------------------------------------- 33 | Static methods defined here: 34 | 35 | __new__(_cls, x, y) 36 | Create new instance of Mytuple(x, y) 37 | 38 | ---------------------------------------------------------------------- 39 | Data descriptors defined here: 40 | 41 | __dict__ 42 | Return a new OrderedDict which maps field names to their values 43 | 44 | x 45 | Alias for field number 0 46 | 47 | y 48 | Alias for field number 1 49 | 50 | ---------------------------------------------------------------------- 51 | Data and other attributes defined here: 52 | 53 | _fields = ('x', 'y') 54 | 55 | ---------------------------------------------------------------------- 56 | Methods inherited from __builtin__.tuple: 57 | 58 | __add__(...) 59 | x.__add__(y) <==> x+y 60 | 61 | __contains__(...) 62 | x.__contains__(y) <==> y in x 63 | 64 | __eq__(...) 65 | x.__eq__(y) <==> x==y 66 | 67 | __ge__(...) 68 | x.__ge__(y) <==> x>=y 69 | 70 | __getattribute__(...) 71 | x.__getattribute__('name') <==> x.name 72 | 73 | __getitem__(...) 74 | x.__getitem__(y) <==> x[y] 75 | 76 | __getslice__(...) 77 | x.__getslice__(i, j) <==> x[i:j] 78 | 79 | Use of negative indices is not supported. 80 | 81 | __gt__(...) 82 | x.__gt__(y) <==> x>y 83 | 84 | __hash__(...) 85 | x.__hash__() <==> hash(x) 86 | 87 | __iter__(...) 88 | x.__iter__() <==> iter(x) 89 | 90 | __le__(...) 91 | x.__le__(y) <==> x<=y 92 | 93 | __len__(...) 94 | x.__len__() <==> len(x) 95 | 96 | __lt__(...) 97 | x.__lt__(y) <==> x<y 98 | 99 | __mul__(...) 100 | x.__mul__(n) <==> x*n 101 | 102 | __ne__(...) 103 | x.__ne__(y) <==> x!=y 104 | 105 | __rmul__(...) 106 | x.__rmul__(n) <==> n*x 107 | 108 | __sizeof__(...) 109 | T.__sizeof__() -- size of T in memory, in bytes 110 | 111 | count(...) 112 | T.count(value) -> integer -- return number of occurrences of value 113 | 114 | index(...) 115 | T.index(value, [start, [stop]]) -> integer -- return first index of value. 116 | Raises ValueError if the value is not present. 117 118 Mytuple 119 120 Mytuple
5、双向队列(deque)
一个线程安全的双向队列

1 class deque(object): 2 """ 3 deque([iterable[, maxlen]]) --> deque object 4 5 Build an ordered collection with optimized access from its endpoints. 6 """ 7 def append(self, *args, **kwargs): # real signature unknown 8 """ Add an element to the right side of the deque. """ 9 pass 10 11 def appendleft(self, *args, **kwargs): # real signature unknown 12 """ Add an element to the left side of the deque. """ 13 pass 14 15 def clear(self, *args, **kwargs): # real signature unknown 16 """ Remove all elements from the deque. """ 17 pass 18 19 def count(self, value): # real signature unknown; restored from __doc__ 20 """ D.count(value) -> integer -- return number of occurrences of value """ 21 return 0 22 23 def extend(self, *args, **kwargs): # real signature unknown 24 """ Extend the right side of the deque with elements from the iterable """ 25 pass 26 27 def extendleft(self, *args, **kwargs): # real signature unknown 28 """ Extend the left side of the deque with elements from the iterable """ 29 pass 30 31 def pop(self, *args, **kwargs): # real signature unknown 32 """ Remove and return the rightmost element. """ 33 pass 34 35 def popleft(self, *args, **kwargs): # real signature unknown 36 """ Remove and return the leftmost element. """ 37 pass 38 39 def remove(self, value): # real signature unknown; restored from __doc__ 40 """ D.remove(value) -- remove first occurrence of value. """ 41 pass 42 43 def reverse(self): # real signature unknown; restored from __doc__ 44 """ D.reverse() -- reverse *IN PLACE* """ 45 pass 46 47 def rotate(self, *args, **kwargs): # real signature unknown 48 """ Rotate the deque n steps to the right (default n=1). If n is negative, rotates left. """ 49 pass 50 51 def __copy__(self, *args, **kwargs): # real signature unknown 52 """ Return a shallow copy of a deque. """ 53 pass 54 55 def __delitem__(self, y): # real signature unknown; restored from __doc__ 56 """ x.__delitem__(y) <==> del x[y] """ 57 pass 58 59 def __eq__(self, y): # real signature unknown; restored from __doc__ 60 """ x.__eq__(y) <==> x==y """ 61 pass 62 63 def __getattribute__(self, name): # real signature unknown; restored from __doc__ 64 """ x.__getattribute__('name') <==> x.name """ 65 pass 66 67 def __getitem__(self, y): # real signature unknown; restored from __doc__ 68 """ x.__getitem__(y) <==> x[y] """ 69 pass 70 71 def __ge__(self, y): # real signature unknown; restored from __doc__ 72 """ x.__ge__(y) <==> x>=y """ 73 pass 74 75 def __gt__(self, y): # real signature unknown; restored from __doc__ 76 """ x.__gt__(y) <==> x>y """ 77 pass 78 79 def __iadd__(self, y): # real signature unknown; restored from __doc__ 80 """ x.__iadd__(y) <==> x+=y """ 81 pass 82 83 def __init__(self, iterable=(), maxlen=None): # known case of _collections.deque.__init__ 84 """ 85 deque([iterable[, maxlen]]) --> deque object 86 87 Build an ordered collection with optimized access from its endpoints. 88 # (copied from class doc) 89 """ 90 pass 91 92 def __iter__(self): # real signature unknown; restored from __doc__ 93 """ x.__iter__() <==> iter(x) """ 94 pass 95 96 def __len__(self): # real signature unknown; restored from __doc__ 97 """ x.__len__() <==> len(x) """ 98 pass 99 100 def __le__(self, y): # real signature unknown; restored from __doc__ 101 """ x.__le__(y) <==> x<=y """ 102 pass 103 104 def __lt__(self, y): # real signature unknown; restored from __doc__ 105 """ x.__lt__(y) <==> x<y """ 106 pass 107 108 @staticmethod # known case of __new__ 109 def __new__(S, *more): # real signature unknown; restored from __doc__ 110 """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ 111 pass 112 113 def __ne__(self, y): # real signature unknown; restored from __doc__ 114 """ x.__ne__(y) <==> x!=y """ 115 pass 116 117 def __reduce__(self, *args, **kwargs): # real signature unknown 118 """ Return state information for pickling. """ 119 pass 120 121 def __repr__(self): # real signature unknown; restored from __doc__ 122 """ x.__repr__() <==> repr(x) """ 123 pass 124 125 def __reversed__(self): # real signature unknown; restored from __doc__ 126 """ D.__reversed__() -- return a reverse iterator over the deque """ 127 pass 128 129 def __setitem__(self, i, y): # real signature unknown; restored from __doc__ 130 """ x.__setitem__(i, y) <==> x[i]=y """ 131 pass 132 133 def __sizeof__(self): # real signature unknown; restored from __doc__ 134 """ D.__sizeof__() -- size of D in memory, in bytes """ 135 pass 136 137 maxlen = property(lambda self: object(), lambda self, v: None, lambda self: None) # default 138 """maximum size of a deque or None if unbounded""" 139 140 141 __hash__ = None 142 143 deque
注:既然有双向队列,也有单项队列(先进先出 FIFO )

1 class Queue: 2 """Create a queue object with a given maximum size. 3 4 If maxsize is <= 0, the queue size is infinite. 5 """ 6 def __init__(self, maxsize=0): 7 self.maxsize = maxsize 8 self._init(maxsize) 9 # mutex must be held whenever the queue is mutating. All methods 10 # that acquire mutex must release it before returning. mutex 11 # is shared between the three conditions, so acquiring and 12 # releasing the conditions also acquires and releases mutex. 13 self.mutex = _threading.Lock() 14 # Notify not_empty whenever an item is added to the queue; a 15 # thread waiting to get is notified then. 16 self.not_empty = _threading.Condition(self.mutex) 17 # Notify not_full whenever an item is removed from the queue; 18 # a thread waiting to put is notified then. 19 self.not_full = _threading.Condition(self.mutex) 20 # Notify all_tasks_done whenever the number of unfinished tasks 21 # drops to zero; thread waiting to join() is notified to resume 22 self.all_tasks_done = _threading.Condition(self.mutex) 23 self.unfinished_tasks = 0 24 25 def task_done(self): 26 """Indicate that a formerly enqueued task is complete. 27 28 Used by Queue consumer threads. For each get() used to fetch a task, 29 a subsequent call to task_done() tells the queue that the processing 30 on the task is complete. 31 32 If a join() is currently blocking, it will resume when all items 33 have been processed (meaning that a task_done() call was received 34 for every item that had been put() into the queue). 35 36 Raises a ValueError if called more times than there were items 37 placed in the queue. 38 """ 39 self.all_tasks_done.acquire() 40 try: 41 unfinished = self.unfinished_tasks - 1 42 if unfinished <= 0: 43 if unfinished < 0: 44 raise ValueError('task_done() called too many times') 45 self.all_tasks_done.notify_all() 46 self.unfinished_tasks = unfinished 47 finally: 48 self.all_tasks_done.release() 49 50 def join(self): 51 """Blocks until all items in the Queue have been gotten and processed. 52 53 The count of unfinished tasks goes up whenever an item is added to the 54 queue. The count goes down whenever a consumer thread calls task_done() 55 to indicate the item was retrieved and all work on it is complete. 56 57 When the count of unfinished tasks drops to zero, join() unblocks. 58 """ 59 self.all_tasks_done.acquire() 60 try: 61 while self.unfinished_tasks: 62 self.all_tasks_done.wait() 63 finally: 64 self.all_tasks_done.release() 65 66 def qsize(self): 67 """Return the approximate size of the queue (not reliable!).""" 68 self.mutex.acquire() 69 n = self._qsize() 70 self.mutex.release() 71 return n 72 73 def empty(self): 74 """Return True if the queue is empty, False otherwise (not reliable!).""" 75 self.mutex.acquire() 76 n = not self._qsize() 77 self.mutex.release() 78 return n 79 80 def full(self): 81 """Return True if the queue is full, False otherwise (not reliable!).""" 82 self.mutex.acquire() 83 n = 0 < self.maxsize == self._qsize() 84 self.mutex.release() 85 return n 86 87 def put(self, item, block=True, timeout=None): 88 """Put an item into the queue. 89 90 If optional args 'block' is true and 'timeout' is None (the default), 91 block if necessary until a free slot is available. If 'timeout' is 92 a non-negative number, it blocks at most 'timeout' seconds and raises 93 the Full exception if no free slot was available within that time. 94 Otherwise ('block' is false), put an item on the queue if a free slot 95 is immediately available, else raise the Full exception ('timeout' 96 is ignored in that case). 97 """ 98 self.not_full.acquire() 99 try: 100 if self.maxsize > 0: 101 if not block: 102 if self._qsize() == self.maxsize: 103 raise Full 104 elif timeout is None: 105 while self._qsize() == self.maxsize: 106 self.not_full.wait() 107 elif timeout < 0: 108 raise ValueError("'timeout' must be a non-negative number") 109 else: 110 endtime = _time() + timeout 111 while self._qsize() == self.maxsize: 112 remaining = endtime - _time() 113 if remaining <= 0.0: 114 raise Full 115 self.not_full.wait(remaining) 116 self._put(item) 117 self.unfinished_tasks += 1 118 self.not_empty.notify() 119 finally: 120 self.not_full.release() 121 122 def put_nowait(self, item): 123 """Put an item into the queue without blocking. 124 125 Only enqueue the item if a free slot is immediately available. 126 Otherwise raise the Full exception. 127 """ 128 return self.put(item, False) 129 130 def get(self, block=True, timeout=None): 131 """Remove and return an item from the queue. 132 133 If optional args 'block' is true and 'timeout' is None (the default), 134 block if necessary until an item is available. If 'timeout' is 135 a non-negative number, it blocks at most 'timeout' seconds and raises 136 the Empty exception if no item was available within that time. 137 Otherwise ('block' is false), return an item if one is immediately 138 available, else raise the Empty exception ('timeout' is ignored 139 in that case). 140 """ 141 self.not_empty.acquire() 142 try: 143 if not block: 144 if not self._qsize(): 145 raise Empty 146 elif timeout is None: 147 while not self._qsize(): 148 self.not_empty.wait() 149 elif timeout < 0: 150 raise ValueError("'timeout' must be a non-negative number") 151 else: 152 endtime = _time() + timeout 153 while not self._qsize(): 154 remaining = endtime - _time() 155 if remaining <= 0.0: 156 raise Empty 157 self.not_empty.wait(remaining) 158 item = self._get() 159 self.not_full.notify() 160 return item 161 finally: 162 self.not_empty.release() 163 164 def get_nowait(self): 165 """Remove and return an item from the queue without blocking. 166 167 Only get an item if one is immediately available. Otherwise 168 raise the Empty exception. 169 """ 170 return self.get(False) 171 172 # Override these methods to implement other queue organizations 173 # (e.g. stack or priority queue). 174 # These will only be called with appropriate locks held 175 176 # Initialize the queue representation 177 def _init(self, maxsize): 178 self.queue = deque() 179 180 def _qsize(self, len=len): 181 return len(self.queue) 182 183 # Put a new item in the queue 184 def _put(self, item): 185 self.queue.append(item) 186 187 # Get an item from the queue 188 def _get(self): 189 return self.queue.popleft() 190 191 Queue.Queue