Python Cultivation 2

Python Development Ide:pycharm, Elipse

1. Operators

　　　　

1        1. Arithmetic operation   +  -*///  * *  % 2  3 2. Assignment operation   A = 1   a + = 2
   
     4 
     5 3. Comparison operation    1>3  
     6 
     7 4. Logical Operation    
    or
    and 1>3 8  9 5. Member Operation     "ab"in   /not
      in    "abce"
   

Number (int)

                       Int Common operation converts                           a string to a numeric int ("123") to                           view the data type              (                           10        ) convert the binary to the default of the binary of the =2/ 8/16)                           Current number, at least binary N-bit       num.bit_length ()

View Code 　　　　　　　　　　

String (str)

#capiltalize First Letter CapitalA ="SB"Print(A.capitalize ()) Casefold Lowera="Sb"Print(A.casefold ())#lowercase But unknown to other countriesPrint(A.lower ())#lower for common variable lowercasea="Sdjha"         Print(A.lower ())#into lowercasePrint(A.upper ())#into uppercaseCenter#Set the width and center the set contentA ="Sb"Print(A.center (20,"*"))>>>*********sb*********#set width, Align leftTest ="Alex"v= Test.ljust (20,"*")Print(v)#set width, align rightTest ="Alex"v= Test.rjust (20,"*")Print(v) Count#index The number of occurrences of the character or concatenated character (look for the number of occurrences of the subsequence)A ="Sb" Print(A.count ("b"))>> 1Test="ALEXALEXR"In fact and end position v= Test.count ('ex', 5,6)Print(v) endswith/does StartsWith end with what begins with a="Sb"Print(A.endswith ("b"))Print(A.startswith ("b") )>>True>>False#￥￥￥expandtabs (), Segmentation (tab use) through \ tTest ="Username\temail\tpassword\nlaiying\[email Protected]\t123\nlaiying\[email Protected]\t123\nlaiying\[email Protected]\t123"v= Test.expandtabs (20)Print(v)#￥￥￥￥ndex index position, can not find errorA ="Sb"Print(A.index ("b"))>>1#￥￥￥￥￥find index position, location is not found-1A ="Sb"Print(A.find ("b") )>>1#format formatting, specifying a value for a string positionA ='I Love{name} {a}'Print(A.format (name =' You', a ="jingjing"))#>>>i Love Jingjing#Format_map # Return the keys value to name aA ='I Love{name} {a}'Print(A.format_map ({"name":' You',"a":"jingjing"}))#"" I lov eyou,jingjinga="pidalfj1233"   #whether the string contains only alphanumericPrint(A.isalnum ()) "Truea="ABC"                #whether the character passed is a letter, a manPrint(A.isalpha ()) "True test="as2df"v= Test.isalpha ()#whether the current input is a number  Print(v) issspace ()#is not a spaceA ="   "Print(A.isspace ())>>True#whether there are non-visible characters#\ t Tab#\ nthe line break#SpaceTest ="oiuas\tdfkj"v=test.isprintable ()Print(v)#determine if all are spacesb =""v=b.isspace ()Print(v)#istiltle #是不是标题 (capital letters)A =" is the men"Print(A.istitle ()#isupper islowerA ="Aa"Print(A.isupper ())#are they all uppercase?Print(A.islower ())#are they all lowercase?#$$$$$$ each element in a string to be spliced with a specified delimiterTest ="you are the wind, I am the sand"Print(test) T=' 'v="_". Join (Test)Print(v)>>>you are the wind, I am the sand>>>You _ is _ the Wind _ son _ i _ is _ Sha#$ $lstrip/rstrip/strip #remove The left side of the space/right space/left and right space (specify the parameters to delete the characters inside)A ="ABC c"Print(A.lstrip ())Print(A.rstrip ())Print(A.strip ()) Example: Remove the specified string with a limited maximum match test="xa"v= Test.lstrip ('xa') v= Test.rstrip ('9lexxexa') v= Test.strip ('xa')Print(v)#Split to specified number#v = test.split (' s ', 2)#Print (v)#Test.rsplit ()#split, only according to, True,false: whether to keep line breaksTest ="ASDFADFASDF\NASDFASDF\NADFASDF"v=test.splitlines (False)Print(v)#uppercase and lowercase conversionsTest ="ALex"v=test.swapcase ()Print(v)#letter, number, underline: identifier Def classA ="def"v=A.isidentifier ()Print(v)#replaces the specified string with the specified stringTest ="Alexalexalex"v= Test.replace ("ex",'BBB')Print(v) v= Test.replace ("ex",'BBB', 2)Print(v)

View Code

Common: Join split find strip upper lower lower replace

　　　　　Str simple operation

　　　　　　　Slice Str[0:2] # refers from the first to the second character

Index subscript to get a string in a string str[2]

······

　　　　　　

　　　　　　　　

　　　　　　　　　　　　

Python Cultivation 2