python3 Foundations "built-running instance of function (1)"

1.type: View the current type of string

 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

 

2.bit_length: View the current system of how many secondary figures

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

 

3.capitalize: The first letter capitalized

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

 

4. (casefold, lower): all letters to lower case, casefold enable more unknown strain lowercase

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

 

5.swapcase: uppercase conversion

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

 

6.center: set the width and center the contents

1  # * Blank filled unknown 
2 Test = " ASD " 
. 3 V = test.center (20 is)    # 20 is to refer to the length 
. 4 V1 = test.center (20 is, " . 9 " )
 . 5  Print (V, V1)
1 >> 99999999asd999999999 by asd

 

7. (ljust (left), the rjust (Right)): arbitrarily specified width, fill character

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

 

8.zfill: String filling, you can not specify a character to fill

1 test="123"
2 v=test.zfill(20)
3 print(v)
1 >>00000000000000000123

 

9.counter: to find a string of number sequences appear

. 1 Test = " alasddslaw " 
2 V = test.count ( " A " )
 . 3 V1 = test.count ( ' SD ' )
 . 4 V2 = test.count ( ' A ' , 5)        # denotes the fifth from the beginning to find 
5 test.count = V3 ( ' A ' , 5,6)       # indicates start looking from the fifth to the sixth end 
. 6  Print (V, V1, V2, V3)
 . 7  
. 8 >> 0. 3. 1. 1

 

10. (endswith, startswith): Analyzing fixed end \ Start

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

11.expendtabs: punctuation

1 test='username\temail\tpassword\nxiaozhou\[email protected]\t123\nxiaoli\[email protected]\t345\nxiaowang\[email protected]\t789\n'
2 v=test.expandtabs(20)
3 print(v)
4 
5 >>
6 username            email               password
7 xiaozhou            [email protected]           123
8 xiaoli              [email protected]            345
9 xiaowang            [email protected]          789

 

12. The split only according to: confirm whether to keep wrap true, false \ n

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']

 

13.find: look for strings, output -1 not found

. 1 Test = " alexalex " 
2  # if not found, the output: -1 
. 3 V = test.find ( ' X ' )
 . 4  Print (V)
 . 5  
. 6 >>. 3

 

14.index: index, an error can not find it

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

 

15.format: formatting a string placeholder with the value specified

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

 

16.isalnum: string contains only letters and numbers

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

 

17.isidentifier: Analyzing letters, underline, identifier

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

 

18. (isdecimal, isdigit, isnumeric): determining whether a digital

1 Test = INPUT ( ' Please Enter STR or int: ' ) # example: 1, two 
2 V1 = test.isdecimal ()
 . 3 V2 = test.isdigit ()
 . 4 V3 = test.isnumeric () # support Chinese figures 
. 5  Print (v1, v2, v3)

 

19.keyword Module: Displays the current version all keywords

. 1  Import keyword
 2 keyword.kwlist    # output command window

 

20.isprintable: determining whether the character is not displayed or can not output, \ T tab, \ n-newline

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

 

If inadequate, please correct me!

 

 

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Origin www.cnblogs.com/wangwenchao/p/11330705.html