python3基础之“函数（1）”

 1 c='123'
 2 print(type(c),c)
 3 b= int(c)
 4 print(type(b),b)
 5 
 6 num="01010"
 7 a=int(num,base=16)
 8 print(a)
 9 
10 >><class 'str'> 123
11 >><class 'int'> 123

1 a=10
2 v=a.bit_length()
3 print(v)
4 
5 >>4

1 test="aLse"
2 v=test.capitalize()
3 print(v)
4 
5 >>Alse

1 test="ASD"
2 v1=test.casefold()
3 print(v1)
4 v2=test.lower()
5 print(v2)

1 a="ABC"
2 c=a.swapcase()
3 print(v)
4 
5 >>abc

1 test="alex"
2 v=test.swapcase()
3 print(v)

1 >>ALEX

1 # *空白未知填充
2 test="asd"
3 v=test.center(20)   # 20指代长度
4 v1=test.center(20,"9")
5 print(v,v1)

1 >>        asd          99999999asd999999999

1 test="asd"
2 v=test.ljust(20,"%")
3 v1=test.rjust(20,"%")
4 print(v)
5 print(v1)
6 
7 >>asd%%%%%%%%%%%%%%%%%
8 >>%%%%%%%%%%%%%%%%%asd

1 test="123"
2 v=test.zfill(20)
3 print(v)

1 >>00000000000000000123

1 test="alasddslaw"
2 v=test.count("a")
3 v1=test.count('sd')
4 v2=test.count('a',5)       #表示从第五个开始找
5 v3=test.count('a',5,6)      #表示从第五个开始找，到第六个结束
6 print(v,v1,v2,v3)
7 
8 >>3 1 1 0

1 test="abc"
2 v=test.endswith('c')
3 v=test.startswith('a')
4 print(v)
5 
6 >>True

1 test='username\temail\tpassword\nxiaozhou\twww@q.com\t123\nxiaoli\tqqq@.com\t345\nxiaowang\tsdfjd@.com\t789\n'
2 v=test.expandtabs(20)
3 print(v)
4 
5 >>
6 username            email               password
7 xiaozhou            www@q.com           123
8 xiaoli              qqq@.com            345
9 xiaowang            sdfjd@.com          789

1 test="assdsfdg\nsjfdhsdef\nksf"
2 v1=test.splitlines(False)
3 v2=test.splitlines(True)
4 print(v1)
5 print(v2)
6 
7 >>['assdsfdg', 'sjfdhsdef', 'ksf']
8 >>['assdsfdg\n', 'sjfdhsdef\n', 'ksf']

1 test="alexalex"
2 # 如果未找到，输出结果：-1
3 v=test.find('x')
4 print(v)
5 
6 >>3

1 test="qwert"
2 v=test.index('q')
3 print(v)
4 
5 >>0

1 test='i am {name},age{a}'
2 v=test.format(name='xiaowang' ,a='18')
3 print(v)
4 
5 >>i am xiaowang,age18

1 test="123"
2 v=test.isalnum()
3 print(v)
4 
5 >>True

1 a="def"
2 v=a.isidentifier()
3 print(v)
4 
5 >>True

1 test=input('please enter  int or str:') #例如：1，二
2 v1=test.isdecimal()
3 v2=test.isdigit()
4 v3=test.isnumeric() #支持中文数字
5 print(v1,v2,v3)

1 import keyword
2 keyword.kwlist   #在命令窗口中输出

1 test="asdfghj"
2 v=test.isprintable()
3 print(v)
4 
5 >>True