Ch 2 - Operators in Python

Python divides the operators into the following seven groups:

• Python divides the operators into the following seven groups:
• Arithmetic operators
• Assignment operators
• Comparison operators
• Logical operators
• Identity operators
• Membership operators
• Bitwise operators

Arithmetic operators

Floor Division

+ And * Operators Can Act on Strings

String Concatenation using + Operator

>>> x = 'johanth'
>>> y = 'yada'
>>> x + y
'johanthyada'


String repetition using * Operator

>>> x*3
'johanthjohanthjohanth'

This phenomenon is over-loading of operator.

>>> a = 5
>>> b = 6
>>> a + b
11
>>> a = "rakesh"
>>> b = "vikash"
>>> a + b
'rakeshvikash'
>>> 
>>> a = 5
>>> b = 6
>>> a*b
30
>>> a = "rakesh"
>>> b = 'vikash'
>>> a * 3
'rakeshrakeshrakesh'
>>> b * 2
'vikashvikash'
>>> 
>>> l = ['rakesh', 'vikash', 'ashish']
>>> l * 3
['rakesh', 'vikash', 'ashish', 'rakesh', 'vikash', 'ashish', 'rakesh', 'vikash', 'ashish']
>>> 

+ And * Operators Can Act on Lists

>>> l = ['rakesh', 'vikash', 'ashish']
>>> l * 3
['rakesh', 'vikash', 'ashish', 'rakesh', 'vikash', 'ashish', 'rakesh', 'vikash', 'ashish']
>>> k = ['johanth', 'sonia']
>>> l + k
['rakesh', 'vikash', 'ashish', 'johanth', 'sonia']
>>> 

Assignment Operators

Python does not have ++ (as in i++) operator.

If you want to increment a variable:

x += 1

Assignment Operator (Problem)

• What is the output of this program?
• x = 5
• y = 10
• x = y
• print(x)
• print(y)

Assignment Operator (Solution)

• What is the output of this program?
• x = 5 # x is the variable name. Explicit value being passed is 5.
• y = 10 # y is the variable name. Explicit value being passed is 10.
• x = y # Variable which is taking the value is on the left. X is taking the value. And value being passed is 10 through y.
• print(x)
• print(y)

The answer is:

10
10
  

Comparison Operators

Logical Operators

“and” in C++ is: &&

“or” in C++ is: ||

>>> x = 6
>>> y = x < 7
>>> y
True
>>> not y
False
>>> not(y)
False
>>>   

Truth Table For ‘and’ 

If both expressions are True, then it will return True.


  

    
Left Side Exp
    
Right Side Exp
    
Overall Result
  

  

    
True
    
True
    
True
  

  

    
False
    
True
    
False
  

  

    
True
    
False
    
False
  
  

    
False
    
False
    
False
  

Identity Operators

Membership Operators

>>> l
['rakesh', 'vikash', 'ashish']
>>> 'rakesh' in l
True
>>> 'sonia' in l
False
>>>   

Bitwise Operators

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