python的数据类型
一、数字类型和字符串类型
1.bin()函数将十进制转换成而进制
2.oct()函数将十进制转换成八进制
3.hex()函数将十进制转换成十六进制
十六进制表示：0-9 a b c d e f
4.数字类型的特性：
只能存放一个值
一经定义，不可更改
直接访问
分类：整型，布尔，浮点，复数
5.字符串类型
引号包含的都是字符串类型
S1='hello world' s="hello world"
s2="""hello world"""
s3='''hello world'''
单引双引没有区别
6.字符串的常用操作
strip()移除空白，也可以去除其他的字符
slipt()分割,默认以空格分割。也可以以其他的字符分割
len()长度 切片：如print(x[1:3])也是顾头不顾尾
print(x[0:5:2])#0 2 4
capitalize()首字母大写
center()居中显示例如：x='hello' print(x.center(30,'#'))
count():计数，顾头不顾尾，统计某个字符的个数，空格也算一个字符
endswith()以什么结尾
satrtswith()以什么开头
find()查找字符的索引位置，如果是负数，代表查找失败
index()索引
find()和index()的区别，如下图：
format()字符串格式化
1.msg='name:{},age:{},sex:{}'
print(msg.format('haiyan',18,女))
2.msg='name:{0},age:{1},sex:{0}'
print(msg.format('aaaaaa','bbbbbb'))
3.msg='name:{x},age:{y,sex:{z}'
print(msg.format(x='haiyan',y='18',z='女'))
isdigit()判断是否是数字
islower()判断是否是全部小写
isupper()判断是否是全部大写
lower()全部转换为小写
upper()全部转换为大写
isspace()判断是否是全都是空格
istitle()判断是否是标题（首字母大写）
swapcase()大小写字母翻转
join()连接
repalce()替换
msg='hello alex'
print(msg.replace('e'),'A',1)
print(msg.replace('e'),'A',2)
ljust()左对齐
X='ABC' print(x.ljust(10,'*'))
二、字符串格式化和字符串的一些方法
1.%s,%d
举例1：name='egon'
age=20
print("my name is %s my age is %s" %(name,age))#%s既能接受字符串，也能接受数字
print(‘my name is %s my age is %d’ %(name,age))#%d只能接受数字
举例2：用户信息的显示
1 while True:
2 name=input("name:")
3 age=input("age:")
4 sex=input("sex:")
5 height=input("height:")
6 msg='''
7 ------------%s info-----------
8 name:%s
9 age:%s
10 sex:%s
11 height:%s
12 ------------------------------
13 '''%(name,name,age,sex,heigth)
14 print(msg)
运行结果如下：
2.字符串方法
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# name='egon' #name=str('egon')# print(type(name))#优先掌握#1.移除空白strip# msg=' hello '# print(msg)# print(msg.strip())# 移除‘*’# msg='***hello*********'# msg=msg.strip('*')# print(msg)#移除左边的# print(msg.lstrip('*'))#移除右边的# print(msg.rstrip('*'))#用处while True: name=input('user: ').strip() password=input('password: ').strip() if name == 'egon' and password == '123': print('login successfull')#切分split# info='root:x:0:0::/root:/bin/bash'# print(info[0]+info[1]+info[2]+info[3])# user_l=info.split(':')# print(user_l[0])# msg='hello world egon say hahah'# print(msg.split()) #默认以空格作为分隔符#cmd='download|xhp.mov|3000'# cmd_l=cmd.split('|')# print(cmd_l[1])# print(cmd_l[0])# print(cmd.split('|',1))#用处while True: cmd=input('>>: ').strip() if len(cmd) == 0:continue cmd_l=cmd.split() print('命令是:%s 命令的参数是:%s' %(cmd_l[0],cmd_l[1]))#长度len# print(len('hell 123'))#索引# 切片:切出子字符串# msg='hello world'# print(msg[1:3]) #1 2# print(msg[1:4]) #1 2 3# 掌握部分oldboy_age=84while True: age=input('>>: ').strip() if len(age) == 0: continue if age.isdigit(): age=int(age) else: print('must be int')#startswith,endswith# name='alex_SB'# print(name.endswith('SB'))# print(name.startswith('alex'))#replace# name='alex say :i have one tesla,my name is alex'# print(name.replace('alex','SB',1))# print('my name is %s my age is %s my sex is %s' %('egon',18,'male'))# print('my name is {} my age is {} my sex is {}'.format('egon',18,'male'))# print('my name is {0} my age is {1} my sex is {0}:{2}'.format('egon',18,'male'))# print('my name is {name} my age is {age} my sex is {sex}'.format(# sex='male',# age=18,# name='egon'))# name='goee say hello'# # print(name.find('S',1,3)) #顾头不顾尾,找不到则返回-1不会报错,找到了则显示索引# # print(name.index('S')) #同上,但是找不到会报错## print(name.count('S',1,5)) #顾头不顾尾,如果不指定范围则查找所有#join# info='root:x:0:0::/root:/bin/bash'# print(info.split(':'))# l=['root', 'x', '0', '0', '', '/root', '/bin/bash']# print(':'.join(l))#lower,upper# name='eGon'# print(name.lower())# print(name.upper())#了解部分#expandtabs# name='egon\thello'# print(name)# print(name.expandtabs(1))#center,ljust,rjust,zfill# name='egon'# # print(name.center(30,'-'))# print(name.ljust(30,'*'))# print(name.rjust(30,'*'))# print(name.zfill(50)) #用0填充#captalize,swapcase,title# name='eGon'# print(name.capitalize()) #首字母大写,其余部分小写# print(name.swapcase()) #大小写翻转# msg='egon say hi'# print(msg.title()) #每个单词的首字母大写#在python3中num0='4'num1=b'4' #bytesnum2=u'4' #unicode,python3中无需加u就是unicodenum3='四' #中文数字num4='Ⅳ' #罗马数字#isdigt:str,bytes,unicode# print(num0.isdigit())# print(num1.isdigit())# print(num2.isdigit())# print(num3.isdigit())# print(num4.isdigit())#isdecimal:str,unicode# num0='4'# num1=b'4' #bytes# num2=u'4' #unicode,python3中无需加u就是unicode# num3='四' #中文数字# num4='Ⅳ' #罗马数字# print(num0.isdecimal())# # print(num1.)# print(num2.isdecimal())# print(num3.isdecimal())# print(num4.isdecimal())#isnumeric:str,unicode,中文，罗马# num0='4'# num1=b'4' #bytes# num2=u'4' #unicode,python3中无需加u就是unicode# num3='四' #中文数字# num4='Ⅳ' #罗马数字## print(num0.isnumeric())# # print(num1)# print(num2.isnumeric())# print(num3.isnumeric())# print(num4.isnumeric())#is其他# name='egon123'# print(name.isalnum()) #字符串由字母和数字组成# name='asdfasdfa sdf'# print(name.isalpha()) #字符串只由字母组成## name='asdfor123'# print(name.isidentifier())name='egGon'print(name.islower())# print(name.isupper())# print(name.isspace())name='Egon say'print(name.istitle()) |
三、列表
一、列表
作用：多个装备，多个爱好，多门课程，多个女朋友等
定义：[]内可以有多个任意类型的值，逗号分隔
以下是列表的常用操作：
1 l=[1,2,3] #l=list([1,2,3])
2 # print(type(l))
3
4 #pat1===》优先掌握部分
5 # 索引：l=[1,2,3,4,5]
6 print(l[0]) 7 # 切片
8 l=['a','b','c','d','e','f']
9
10 # print(l[1:5])
11 # print(l[1:5:2])
12 # print(l[2:5])
13 # print(l[-1])
14
15
16 #了解
17 # print(l[-1:-4])
18 # print(l[-4:])
19 # l=['a','b','c','d','e','f']
20 # print(l[-2:])
21
22 # 追加
23 # hobbies=['play','eat','sleep','study']
24 # hobbies.append('girls')
25 # print(hobbies)
26
27 # 删除
28 hobbies=['play','eat','sleep','study']
29 # x=hobbies.pop(1) #不是单纯的删除，是删除并且把删除的元素返回，我们可以用一个变量名去接收该返回值
30 # print(x)
31 # print(hobbies)
32
33 # x=hobbies.pop(0)
34 # print(x)
35 #
36 # x=hobbies.pop(0)
37 # print(x)
38
39 #队列：先进先出
40 queue_l=[]
41 #入队
42 # queue_l.append('first')
43 # queue_l.append('second')
44 # queue_l.append('third')
45 # print(queue_l)
46 #出队
47 # print(queue_l.pop(0))
48 # print(queue_l.pop(0))
49 # print(queue_l.pop(0))
50
51
52 #堆栈:先进后出，后进先出
53 # l=[]
54 # #入栈
55 # l.append('first')
56 # l.append('second')
57 # l.append('third')
58 # #出栈
59 # print(l)
60 # print(l.pop())
61 # print(l.pop())
62 # print(l.pop())
63
64 #了解
65 # del hobbies[1] #单纯的删除
66 # hobbies.remove('eat') #单纯的删除，并且是指定元素去删除
67
68
69 # 长度
70 # hobbies=['play','eat','sleep','study']
71 # print(len(hobbies))
72
73 # 包含in
74 # hobbies=['play','eat','sleep','study']
75 # print('sleep' in hobbies)
76
77 # msg='hello world egon'
78 # print('egon' in msg)
79
80
81 ##pat2===》掌握部分
82 hobbies=['play','eat','sleep','study','eat','eat']
83 # hobbies.insert(1,'walk')
84 # hobbies.insert(1,['walk1','walk2','walk3'])
85 # print(hobbies)
86
87 # print(hobbies.count('eat'))
88 # print(hobbies)
89 # hobbies.extend(['walk1','walk2','walk3'])
90 # print(hobbies)
91
92 hobbies=['play','eat','sleep','study','eat','eat']
93 # print(hobbies.index('eat'))
94
95
96 #pat3===》了解部分
97 hobbies=['play','eat','sleep','study','eat','eat']
98 # hobbies.clear()
99 # print(hobbies)
100
101 # l=hobbies.copy()
102 # print(l)
103
104 # l=[1,2,3,4,5]
105 # l.reverse()
106 # print(l)
107
108 l=[100,9,-2,11,32]
109 l.sort(reverse=True)
110 print(l)
