Python Basic Data type

1. Arithmetic operation:

2. Comparison operation:

3. Assignment Operation:

4. Logical Operation:

5. Member Arithmetic:

1, int

Python2 int has range, and long integer type
Python3 all the numbers are int no matter how long

On a 32-bit machine, the number of integers is 32 bits and the value range is -2**31~2**31-1, which is -2147483648~2147483647
On a 64-bit system, the number of integers is 64 bits and the value range is -2**63~2**63-1, which is -9223372036854775808~9223372036854775807

• int is converted to int type, can be converted to such as "123a", default 10 binary

A = "123"
b = Int (a)
B = B + 1000

num = ("0011")
Int (num,base=2) 2 binary conversion

num = "a"
int (num, base=16) 16 binary conversion

• Int.bit_length the binary of the current number at least in several representations

• Range (0,100)

Python 2.7 is now created in memory
Python 3 optimization mechanism, for loop when creating in memory 2, Boolean bool
True or False 1 or 0 3, String str string once created non-modifiable, any modification will create a new copy of the string
methods to keep in mind:　　

1. Join () '. Join (String)
2. Split ()
3. Find ()
4. Strip () according to the longest common sub-sequence
5. Upper ()
6. Lower ()
7. The slice is indexed by the character string [0], the string [0:2]
8. Len (String) string has several characters
9. Iterate for variable name in string
10. Replace replace a number of strings can be replaced with numeric parameters. Replace (string in old string, target substring, number of times)

Test = "Zzhou" # Initial capital print (Test.capitalize ())
# Turn lowercase, casefold more powerful can come out unknown correspondence print (Test.casefold ()) print (Test.lower ())
#center Set the width and center the content by 20-finger width, * The padding character can only have one # and the left padding ljust the right padding Rjust#zfill can be filled with only 0 print (Test.center (20, "*"))
#去字符串中寻找子序列出现的个数, starting position 5 End position 6 is optional print (Test.count ("zz", 5,6))
#以什么什么结尾起始位置5 End position 6 is optional print (Test.endswith ("ou", 5,6))
#以什么什么开头起始位置5 End position 6 is optional print (Test.startswith ("zz", 5,6))
#将tab符转换成空格, the default is 8, which returns a copy of the current string, preceded by a segmentation, and an insufficient bit of the previous one to complement print ("Z\thou". Expandtabs ()) print ("123456\t789". Expandtabs (6)) print ("1\t3456789". Expandtabs (6))
#find from the beginning, find the return index, cannot find return-1. [2,8] and only once #index can not find the error print (Test.find ("H", 2,8))
#format formatting, replace the placeholder print ("I am {name},age{a}") in order or name. Format (name= "Zhou", a=19)) print ("I am {0},age{1}". Format ("Zhou", 19) )
#format_map #format format print with a dictionary ("I am {name},age{a}". Format_map ({"Name": ' Weekly ', "a": 19})
#isalnum whether it is a letter and a digital print (Test.isalnum ())
#isalpha is the letter print ("abc"). Isalnum ())
Isdecimal IsDigit IsNumeric is the number isdigit more powerful such as "②" isnumeric support Chinese test = "123" V1 = Test.isdecimal () v2 = Test.isdigit () v3 = Te St.isnumeric () print (V1,V2)
Isidentifier is the legal identifier a = "str" Print (A.isidentifier ())
# isprintable whether there are non-visible characters such as \tprint ("Org\tsss") in the string. Isprintable ())
Print ("". Isprintable ())
#isspace () Whether all spaces #istitle () are headings each word is capitalized and can be used with the title () print ("Ni Shif eng Re". Title ()) #Ni SHIF Eng reprint ("Ni S  HIF Eng Re ". Istitle ()) #True #*****************join () string each character is spliced by the specified delimiter ******************print (" ". Join (" I-I-i-Owen ")) #我 me I Owen Print ("&". Join ("I-I-i-Owen")) #我 & me & I & Euro & #islower () lower () judged to be lowercase converted to lowercase test = "Zhou" V1 = test.lower () v 2 = Test.islower () print (V1,V2) #isupper () Upper () determines that uppercase is converted to uppercase #lstrip () Rstrip () strip () remove left (\t,\r), right, all spaces can also be added to the parameter, Match as many characters as you need to remove

#S. Strip ([chars]) str

#Return a copy of the string S with leading and trailing
#whitespace removed.
#If chars is given and isn't None, remove characters in chars instead.

Test = "9lexxexa" v = test.rstrip (' xa ') print (v) #str. Maketrans ("abc", "123")  ABC and 123 mappings Replace test = "Testaasa" #partition ()   split into three copies of Test.partition ("s")  te S Taasa#rpartition () by string   divided into three parts test.rpartition ("s")  Testaa s A #split () test.split (' s ') te taa a  can add a parameter to specify the number of splits, but s does not leave behind a regular expression #rsplit ()
#splitlines Split Print ("A\NB\NC") by line break. Splitlines (False)  # = = ' A ', ' B ', ' C ' Print ("A\nb\nc". Splitlines (True))   # = =  ' a\n ', ' b\n ', ' C ' #swapcase ()  case Conversion

　　

Python Basic Data type