Python's is and = = and encoding and decoding

One, is and = =

1.1== comparison, compare = = = value on both sides of the data

1A ='Alex'2b ='Alex'3 Print(A = = b)#True4 5n = 106N1 = 107 Print(n = = n1)#True8 9Li1 = [A]TenLi2 = [A] One Print(Li1 = = Li2)#True

　　

1.1.1id () or Fetch data storage address

1 ' Alex ' 2 Print (ID (a))   # 36942544  memory address 34 n =5print(ID (n))     # 1408197120 6 7 li = [8)print(ID (LI))      #38922760

Is comparison, is the address of the data on both sides

1 #string2A ='Alex'3b ='Alex'4 Print(A isb#True5 #Digital6n = 107N1 = 108 Print(n isN1)#True

1.2 Small Data pools

Small Data pool range for 1.2.1 numbers-5 to 256 (including-5 and 256)

1.2.2 Small Data pool range for strings

Single character *20, data store address is different

The data store has a different address if there are special characters in the string

1A ='[email protected]'2A1 ='[email protected]'3 Print(A isA1)#Fales4 5n = 5//26N1 = 27 Print(n isN1)#True8 9A ='a'*21Tenb ='a'*21 One Print(A isb) # False  A  -A ='aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa' -b ='aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa' the Print(A isb

Second, encoding and decoding

First look at several common coding methods:

ASCII code: is used to denote English, which is expressed in 1 bytes, where the first digit is 0 and the other 7 bits store data, which can represent 128 characters altogether.

GBK /gb2312/gb18030: The represents the kanji. gbk/gb2312 represents Simplified Chinese, GB18030 means traditional Chinese, and a character is represented by 16 bits.

Unicode encoding: contains all the characters in the world, is a character set, and 32 bits represents one character.

UTF-8: is one of the ways Unicode characters are implemented, which uses 1-4 characters to represent a symbol, varying the length of a byte depending on the symbol .

English          8-bit

European text 16-bit

Chinese 24-bit

2.1 encoding

encode (encoded) in parentheses specifies what type of encoding to encode into. The corresponding byte

after getting the encoding

 1  s =  "  Alex   " 2  s1 =  "  are you hungry   " 3  print  (S.encode (  " utf-8      )) #   b ' Alex '  4  print  (S1.encode (  " utf-8     )) #  b ' \xe9\xa5\xbf\xe4\xba\x86\xe4\xb9\x88 '  

Decode (encoded) decodes the encoded bytecode into the corresponding plaintext

1s ='Alex'2S1 ='are you hungry?'3 Print(S.encode ('Utf-8'))#b ' Alex '4 Print(S1.encode ('Utf-8'))#b ' \xe9\xa5\xbf\xe4\xba\x86\xe4\xb9\x88 '5 6S2 = S1.encode ('Utf-8')#b ' \xe9\xa5\xbf\xe4\xba\x86\xe4\xb9\x88 '7S3 = S2.decode ('Utf-8')#are you hungry?

　　

Python's is and = = and encoding and decoding