Python Tokens

Python Tokens :

1. Keyword 

2. Identifiers 

3. Literals 

4.operators

1. Keyword :

• python keywords are special reserved. words

• special meaning to the compiler

• each keyword have special meaning 

• never use it as variable

 variable : data name

                  Is symbolic name that is reference an object

 

Keyword : 

False      await       else       import      pass

None     break        except    in             raise

True      class         finally     is           return

and       continue    for          lambda  try

as         def             from       nonlocal  while

assert   del            global     not           with

async   elif             if             or              yield

2. Identifiers : 

Identifiers  are the name used to identify a variable, function,  class or object 

Rules :

1. Keyword should not be used as identifier name 

2. Python is case sensitive ( a, A both are different) 

3. First character of identifier can be character and underscore (_) but not digit 

3. Literals in python : 

     # String literal 

     # Numeric literal

     # Boolean literals

     # Special  literal 

      # string literal : any things which return in single and double quote treated as string 

Name = "kanchan"

Name1 = 'kanchan1'

      Multiline string : 3 single quote use

          ''' hello students how are you 

             I hope all are good

             Your exam starts on monday '''

        # Numeric Literal : int , long, float, complex

      Int : + , -  ex: 10, -7

      Long : unlimited int size ex: 152673662

      Float : decimal point  ex: 5782.79

      Complex: a+bj

       # Boolean Literal: can have only 2.        values

                   •True               •False

     # special literal : 

• only 1 special literal:  None 

•Used to specify to the field that is not created 

Val = 10

Val1 = None 

4. Operators : 

            Arithmetic operator : (+ ,- ,* ,/ ,%)

            Used to perform arithmetic.          operations take 2 operand

            a2 , b2 = 10 , 10

            c1=a2 + b2

            c2 = a2*b2 

            c3 = a2/b2

            c4 = a2-b2

             print (c1,c2,c3,c4)

         

            Assignment operators :(= ,+= ,-= ,*=)

            Used to assign value to a variable 

             var = 10

             var = 10

             var += 9               # var = var + 10

             val = 10

             val *= 9       

             str = 15

             str -= 10

              print (var,val,str)

              comparison  operators :(> ,< ,>= ,<=,!= ) used to compare 2 values and return true or false as output                      

               a = 10 

               b = 20 

               val1 = a < b

               var3 = a > b 

               str1 = a <= b

               val2 = a >= b

               var2 = a != b

               print(val1,var3,str1,val2,var2)

              Logical operators :( and, or, not) 

              Used to perform logical.  calculations and return true or false as output 

              c9= a < b and a > b 

              c10 = a < b or a > b

              print ( c9,c10)

 

              bitwise operators : (<< ,>> ,& ,! ,~)

              Used to perform bitwise calculations 

              A = 7 | 5

              B = 7 & 5

            #C = 7 ~ 5

              D = 7 >> 5

              E = 7<< 5

              print(A,B,D,E)

             identity operators : ( is, is not) 

             Test if the two operands share an identity 

             A1 = 6

             B1 = 8

             A2 =A1 is 6

             B2 = B1 is not 8

             C= B1 is 8

             NAME = "KANCHAN"

             x = NAME is "KANCHAN"

             print(A2,B2,C,x)

            Membership operators : ( in, not in) 

            Test whether a value  is a member of a sequence 

            name = ['kanchan','koyal','monali']

            X = 'kanchan' in name

            X1 = 'yal' in name

            x1 = 'yal' in 'koyal'

            x2 = "koyal" not in name

            print(X,X1,x1,x2)