第三天学习总结

#######################list 类 列表########################
li = [1, 2, 343, 'dfas', ['fsad', 'dfas'], True]
# list 是一个集合 能放任何东西进去
# print(li[0:3])
# list 是可以修改的

# 索引法
# li[1]
# a = li[4][0] value = 'fsad'

# 切片法
# li[3:5] = [3223,3432]

# 列表中的元素是以，分割 一个一个是整体
# li[1] = 'fdasdf'
# print(li)

# in 操作

# for 循环 while循环
tuple
# 删除
# del li[1]
list
#####转换
# 字符串转化为列表 li = list['dfsadfasdf']
#若列表里只有字符串
'''li = ['dfas','fdsaf']
    v = "".join(li)
    print(v)
'''
#列表里不只有字符串 可以使用for循环
'''
s = ""
for itm in li:
    s = s + str(itm)
print(itm)    
'''
# list类中提供的方法
'''
    l、li.append(self, p_object):  # real signature unknown; restored from __doc__
    """ L.append(object) -> None -- append object to end """
     v = li.append(5) 原值最后追加 v的value 位none
     li.append(['',''])
    2、清空列表
     li.clear()
    3、拷贝
     count(self, value): # real signature unknown; restored from __doc__
     L.count(value) -> integer -- return number of occurrences of value 
    4、计数
     count(self, value): # real signature unknown; restored from __doc__
     L.count(value) -> integer -- return number of occurrences of value 
    5、扩展原列表 参数为可迭代对象：字符串、列表框、元组  注意和append的区别
     extend(self, iterable): # real signature unknown; restored from __doc__
     L.extend(iterable) -> None -- extend list by appending elements from the iterable 
     li = [112,232,3213,3]
     li.append([213,3213])
     print(li)
     [112,232,3213,3,[213,3213]]
     
         li = [112,232,3213,3]
         li.extend([213,3213])
         print(li)
         [112,232,3213,3,213,3213]
    6、根据索引值获取位置 index
      index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__
      L.index(value, [start, [stop]]) -> integer -- return first index of value.
      Raises ValueError if the value is not present.
    7、在指定索引位置插值 insert
     insert(self, index, p_object): # real signature unknown; restored from __doc__
     L.insert(index, object) -- insert object before index 
    8、删除索引对应的值 不指定索引默认最后一个值 并获取删除值
     pop(self, index=None): # real signature unknown; restored from __doc__
     L.pop([index]) -> item -- remove and return item at index (default last).
     Raises IndexError if list is empty or index is out of range.
     li = [112,232,3213,3]
     v = li.[1]
     print(v,li)
     232
     [112,3213,3]    
     9、选择删除值 remove
      remove(self, value): # real signature unknown; restored from __doc__
        """
        L.remove(value) -> None -- remove first occurrence of value.
        Raises ValueError if the value is not present.
        """
# pop remove del li[0]   del li[1:2]
    10、反转 reverse
     reverse(self): # real signature unknown; restored from __doc__
        """ L.reverse() -- reverse *IN PLACE* """
    11、排序 sort
     sort(self, key=None, reverse=False): # real signature unknown; restored from __doc__
        """ L.sort(key=None, reverse=False) -> None -- stable sort *IN PLACE* """
        reverse = False 从小到大排序
#list 有序且可以被修改
    
'''
dict
###########################元组tuple#########################
'''
元组一旦被创建  一级元素不可修改、不能被增加和删除 嵌套的列表框可以修改
tuple 是有序的
可以进行索引
可以进行切片
可以进行for 循环 while循环
最好创建的时候加一个小逗号 tup = (fasdf,fdsfdfd,)
tu = (dfas,erw,rewr,[(33,44)],4234) #获取33
v = tu[3][0][0]
print(v)
33

b = tu[3][0] =234
print(b)
tu = (dfas,erw,rewr,[234],4234)
#############list方法
    1、计数 count
     count(self, value): # real signature unknown; restored from __doc__
     """ T.count(value) -> integer -- return number of occurrences of value """
        return 0
    2、找寻 index
     index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__
     """
     T.index(value, [start, [stop]]) -> integer -- return first index of value.
      Raises ValueError if the value is not present.
      """

'''
############################字典 #############
'''
info = {"k1":v1,"k2":"v2"}  #"k1":"v1" 键值对  
key:value   value 可以为任意值
key : 数字、字符串、元组 都可以  列表不可以 哈希表
#索引使用key值 自己申明的
#无序状态无法切片
#删除
    del info[key]
# for 循环 默认只循环key
    for item in info.keys
    for item in info.values
    for item in info .items  键值对
####or  for item in info.keys
        print(item,info[item])
True 1  False 0 作为key 可能与1 重复
'''
####################dict 常用方法
'''
    1、dict()
    2、clear(self): # real signature unknown; restored from __doc__
        """ D.clear() -> None.  Remove all items from D. """
        pass

    3、 copy(self): # real signature unknown; restored from __doc__
        """ D.copy() -> a shallow copy of D """
        pass

    4、@staticmethod # known case直接写个类名就可以了 静态方法
      fromkeys(*args, **kwargs): # real signature unknown 第一个参数为key 第二个参数为value
        """ Returns a new dict with keys from iterable and values equal to value. """ 创建字典，指定统一的值
        pass

####5、get(self, k, d=None): # real signature unknown; restored from __doc__
        """ D.get(k[,d]) -> D[k] if k in D, else d.  d defaults to None. """
      根据key取value值 key不存在时返回d值 d默认值为none
    6、pop(self, k, d=None): # real signature unknown; restored from __doc__
        """
        D.pop(k[,d]) -> v, remove specified key and return the corresponding value.
        If key is not found, d is returned if given, otherwise KeyError is raised
        删除值 若key值不存在返回d
    7、popitem(self): # real signature unknown; restored from __doc__
        """
        D.popitem() -> (k, v), remove and return some (key, value) pair as a
        2-tuple; but raise KeyError if D is empty.
        """随机删除一对键值对
    8、setdefault(self, k, d=None): # real signature unknown; restored from __doc__
        """ D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D """
        设置值：如果已经存在的key 不设置 获取原对应的value
                若不存在 设置该value
    9、update(self, E=None, **F): # known special case of dict.update
        """
        D.update([E, ]**F) -> None.  Update D from dict/iterable E and F.
        If E is present and has a .keys() method, then does:  for k in E: D[k] = E[k]
        If E is present and lacks a .keys() method, then does:  for k, v in E: D[k] = v
        In either case, this is followed by: for k in F:  D[k] = F[k]
        """
        已经存在 覆盖掉
        不存在 赋值
        dic.update(k1=123,k3=234,k5="dfas") 自动转换成字典 
    



'''
###############################大整理#####################
'''
#数字
    int
#字符串
    replace
    find 
    join
    strip
    startwith
    endwith
    upper
    lower
    format  特殊的 v = template.format(**{name:'fdsa',age:'fdasf'}) 
#列表
    append 
    extend 
    insert
    索引、切片、循环
#元组 忽略
#字典
    get 
    update
    keys
    values
    items
    for 
    索引
#布尔值
0 1 
bool()
为假的:none ()  0  '' [] {}





'''