Python base continuation (base data type)

A holistic initial knowledge data type

1.1int

The number is mainly used for computing, not many ways to use, just remember one can:

# bit_length () when decimal is represented by a binary, the minimum number of bits i = 4print= oneprint3, 4     

1.2bool

There are two types of Boolean values: True,false. is the correct condition of the reaction.

True 1 true.

False 0 false.

1.3str

1.3.1, the index of the string, and the slice.

The index is subscript, that is, the elements of the string begin with the first, the initial index is 0, and so on.

 s =  " abcdefghijklmn  "  print  (S[0]) #  Span style= "COLOR: #008000" > output result a  print  (s[1]) #   output result B  print  (S[5]) #   output result F  print          (S[8]) #   output result I  print          (S[-1]) #   output result n  print          (S[-3]) #   output result L  

A slice is a paragraph that intercepts a string by index (index: Index: STRIDE), forming a new string (the principle is that the head ignores the end)

s ='ABCDEFGHIJKLMN'Print(S[0:7])#output Result: ABCDEFGPrint(S[1:7])#output Result: BCDEFGPrint(s[0:])#output Result: ABCDEFGHIJKLMNPrint(S[5:0:-1])#-1 Reverse plus step output result: FEDCBPrint(S[-1:-5:-1])#the first-1 is the last, the second-1 reverse plus step output result: NmlkPrint(S[-1:-5:-2])#-2 Reverse plus step output result: NL

1.3.2, String Common methods

*capitalize () capital letter, other letters lowercase

s =  'Alex Wusir'print(S.capitalize ())                  #  output: Alex Wusir 

Capitalize

*swapcase () Case reversal

s =  'Alex Wusir'print(S.swapcase ())                  #  Output result: ALEX Wusir

Swapcase

*title () non-letter-separated sections, uppercase, other lowercase

s =  'Alex Wusir1taibai*ritian'print(S.title ())                    #  Output result: Alex Wusir1taibai*ritian

title

Upper ()  all caps
Lower () all lowercase

s =  'alexawusir'print(S.upper ())              #  Output: AlexawusirPrint(S.lower ())              # output: Alexawusir

Upper Lower

Examples used in the CAPTCHA:

' AbCD '  = input (' Please enter your verification code:')if you_code.upper () = = Code.upper ():     Print (' correct ') Else :     Print (' please re-enter ')

Application of Upper

*center (,) centered on what, padding default empty

s =  'Alex Wusir'print(s.center)         # output:     Alex Wusir     print(s.center,'*')    # output Result: Alex wusir*****print(S.center (1))         # output: Alex Wusir

Center (,)

Expandtabs ()

\ t Front of completion

By default, a tab key becomes 8 spaces, if the character in front of the tab is less than 8, then complete 8, if the character in front of the TAB key is more than 8 less than 16, then complete 16, and so on each complement of 8.

s =  'al\tex wusir'print(s.expandtabs ()) output: Al      ex Wusir

Expandtabs

Find () The index through the element, can be found in the whole, can be sliced, cannot find return-1
   Index () through the element to look for indexes, can look for the whole, can slice, can't find the error

s ='ALEXSS dhfgsdjddfdf'Print(S.find ('a'), type (S.find ('a')))Print(S.find ('Alex'), type (S.find ('a')))Print(S.find ('a'))Print(S.find ('a', 1,5))Print(S.find ('L') Output Result: 0<class 'int'>0<class 'int'>0-1-1

Find ()

StartsWith  EndsWith

s ='Alex Wusir'Print(S.startswith ('a'))Print(S.startswith ('Al'))Print(S.startswith ('W', 5))Print(S.startswith ('W', 5))Print(S.endswith ('R'))Print(S.endswith ('R',-1))Print(S.endswith ('u',-4)) Output result: Truetruetruefalsetruetruefalse

startswith EndsWith

Strip () remove spaces, line breaks, tab keys, and so on at both ends of a string
If there is content within (), remove the content, see example

s =  '\talex wusir\n'alalelllllllxwusirbl' Print (S.strip ()) Print (S.lstrip ()) Print (S.rstrip ()) Print (S1.strip ('lab')) output: Alex Wusiralex wusir    Alex Wusirelllllllxwusir 

Strip

Strip Application at Login

Name = input (' Please enter name:'). Strip ()if'Alex' :     Print ('somebody') else:print(' please re-enter ')

Strip

Split str--->list method

s ='Alex;wusir;ritian'S1='Alexalaria'Print(S.split (';'))Print(S1.split ('a'))Print(S1.split ('a', 1) output Result: ['Alex','Wusir','Ritian']["','Lex','L','RI',"']["','Lexalaria']

Split

Replace

' brother and sister , old boy, old boy. '  = s1.replace (' old ',' small '= S1.replace (  ' old ',' small ', 1)print(S2)  Print(S3) output: Sister and brother, Little boy, Little boy, brother and sister, young boy, old boy.

Replace

Isalnum () #字符串由字母或数字组成

Isalpha () #字符串只由字母组成

IsDigit () #字符串只由数字组成

Name='jinxin123'print# string composed of letters or numbers print# A string consists only of letters the print# string is only composed of numbers output: Truefalsefalse

is

Format

s ='I am {} , this year {} years old, height {}cm'. Format ('people', 18,175)Print(s) output: I am a man, 18 years old, height 175cms='I am {0}, this year {1} years old, height {2}cm,{0} The will of the People'. Format ('people', 18,175)Print(s) Output: I am human, 18 years old, height 175cm, people's wishes s='I am {name}, this year {age}, height {high}cm'. Format (name ='people', age = in, high =175)Print(s) output: I am a man, 18 years old, height 175cm

three formatted outputs of format

Count counts the number of occurrences of an element

s =  'alexaaaaa wusir'print(S.count ('a' ) 6

usage of Count

Len  computes the number of string bits

' Alex '   'print(len (s))print(len (S1) ) Output:412

Len

Two: For loop

The user iterates through the contents of an object in order.

Example: Print the elements in a string sequentially

' Salffdsafdsag '  0 while Count < Len (s):    print (S[count])    1# Method for loop: for in s:    print (i)

usage of the For loop

Python base continuation (base data type)