[Sigma]

Operators are special symbols in Python that carry out arithmetic or logical computation. The value that the operator operates on is called the operand.

For example:

>>> 2+3
5

Here, + is the operator that performs addition. 2 and 3 are the operands and 5 is the output of the operation.

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Arithmetic operators
Arithmetic operators are used to performing mathematical operations like addition, subtraction, multiplication etc.

Arithmetic operators in Python

• + Add two operands or unary plus x + y (+2)
  
• - Subtract right operand from the left or unary minus x - y (-2)
  
• * Multiply two operands x y
  
• / Divide left operand by the right one (always results into float) x / y
  
• % Modulus - the remainder of the division of left operand by the right x % y (remainder of x/y)
  
• // Floor division - division that results in the whole number adjusted to the left in the number line x // y
  
• Exponent - left operand raised to the power of right xy (x to the power y)
  
  Example: Arithmetic operators in Python
  x = 15
  y = 4
  
  # Output: x + y = 19
  print('x + y =',x+y)
  
  # Output: x - y = 11
  print('x - y =',x-y)
  
  # Output: x y = 60
  print('x y =',x*y)
  
  # Output: x / y = 3.75
  print('x / y =',x/y)
  
  # Output: x // y = 3
  print('x // y =',x//y)
  
  # Output: x y = 50625
  print('x y =',xy)
  
  
  When you run the program, the output will be:
  
  x + y = 19
  x - y = 11
  x y = 60
  x / y = 3.75
  x // y = 3
  x y = 50625
  
  

  ---

  
  Comparison operators
  
  
  Comparison operators are used to comparing values. It either returns True or False according to the condition.
  
  Comparison operators in Python
  
  • > Greater than - True if the left operand is greater than the right x > y
    
  • < Less than - True if the left operand is less than the right x < y
    
  • == Equal to - True if both operands are equal x == y
    
  • != Not equal to - True if operands are not equal x != y
    
  • >= Greater than or equal to - True if the left operand is greater than or equal to the right x >= y
    
  • <= Less than or equal to - True if the left operand is less than or equal to the right x <= y
    
  
  Example: Comparison operators in Python
  x = 10
  y = 12
  
  # Output: x > y is False
  print('x > y is',x>y)
  
  # Output: x < y is True
  print('x < y is',x<y)
  
  # Output: x == y is False
  print('x == y is',x==y)
  
  # Output: x != y is True
  print('x != y is',x!=y)
  
  # Output: x >= y is False
  print('x >= y is',x>=y)
  
  # Output: x <= y is True
  print('x <= y is',x<=y)
  
  

  ---

  
  Logical operators
  Logical operators are the and, or, not operators.
  
  Logical operators in Python
  
  • and True if both the operands are true x and y
    
  • or True if either of the operands is true x or y
    
  • not True if the operand is false (complements the operand) not x
    
    Example: Logical Operators in Python
    x = True
    y = False
    
    # Output: x and y is False
    print('x and y is',x and y)
    
    # Output: x or y is True
    print('x or y is',x or y)
    
    # Output: not x is False
    print('not x is',not x)
    
    

    ---

    
    Bitwise operators
    Bitwise operators act on operands as if they were a string of binary digits. It operates bit by bit, hence the name. Most of the time these operators are not being used in day to day development. If we are in data science stream then, of course, this would be used a lot. These operators use less memory consumption and computation power than other operators.
    
    For example, 2 is 10 in binary and 7 is 111.
    
    In the table below: Let x = 10 (0000 1010 in binary) and y = 4 (0000 0100 in binary)
    
    Bitwise operators in Python
    
    • & Bitwise AND x& y = 0 (0000 0000)
      
    • | Bitwise OR x | y = 14 (0000 1110)
      
    • ~ Bitwise NOT ~x = -11 (1111 0101)
      
    • ^ Bitwise XOR x ^ y = 14 (0000 1110)
      
    • >> Bitwise right shift x>> 2 = 2 (0000 0010)
      
    • << Bitwise left shift x<< 2 = 40 (0010 1000)
      
    Note: If we perform right shift by one then it results in a divide by 2 and if we perform the left shift by one then it multiplies the number with 2.
    
    Example: Let's consider x as 5 (0101) if we perform the right shift operation by one then it becomes 10 (1010). If we perform the left shift operation by one then x becomes 2 (0010) which is the floor value of 5 divides by 2.
    
    

    ---

    
    Assignment operators
    Assignment operators are used in Python to assign values to variables.
    
    a = 5 is a simple assignment operator that assigns the value 5 on the right to the variable a on the left.
    
    There are various compound operators in Python like a += 5 that adds to the variable and later assigns the same. It is equivalent to a = a + 5.
    
    Assignment operators in Python
    
    • {=}  x=5  {x=5}
      
    • {+=} x +=5 {x=x+5}
      
    • {-=} x-=5 {x=x-5}
      
    • {*=} x*=5 {x=x*5}
      
    • {/=} x/=5 {x=x/5}
      
    • {%=} x%= 5 {x=x%5}
      
    • {//=} x//=5 {x=x//5}
      
    • {=} x=5 {x=x**5}
      
    • {&=} x&=5 {x=x&5}
      
    • {|=x} x|= 5 {x=x|5}
      
    • {^=} x^=5 {x=x^5}
      
    • {>>=} x>>=5 {x=x>>5}
      
    • {<<=} x<<=5 {x=x<<5}
      
    
    

    ---

    
    Special operators
    Python language offers some special type of operators like the identity operator or the membership operator. They are described below with examples.
    
    Identity operators
    is and is not are the identity operators in Python. They are used to check if two values (or variables) are located on the same part of the memory. Two variables that are equal does not imply that they are identical.
    
    Identity operators in Python
    is True if the operands are identical (refer to the same object) {x is True}
    is not True if the operands are not identical (do not refer to the same object) {x is not True}
    
    Example: Identity operators in Python
    x1 = 5
    y1 = 5
    x2 = 'Hello'
    y2 = 'Hello'
    x3 = [1,2,3]
    y3 = [1,2,3]
    
    # Output: False
    print(x1 is not y1)
    
    # Output: True
    print(x2 is y2)
    
    # Output: False
    print(x3 is y3)
    
    
    Here, we see that x1 and y1 are integers of the same values, so they are equal as well as identical. Same is the case with x2 and y2 (strings).
    
    But x3 and y3 are the list. They are equal but not identical. It is because interpreter locates them separately in memory although they are equal.
    
    

    ---

    
    Membership operators
    in and not in are the membership operators in Python. They are used to test whether a value or variable is found in a sequence (string, list, tuple, set and dictionary).
    
    In a dictionary, we can only test for the presence of a key, not the value.
    
    in True if value/variable is found in the sequence {5 in x}
    not in True if value/variable is not found in the sequence {5 not in x}
    
    Example: Membership operators in Python
    x = 'Hello world'
    y = {1:'a',2:'b'}
    
    # Output: True
    print('H' in x)
    
    # Output: True
    print('hello' not in x)
    
    # Output: True
    print(1 in y)
    
    # Output: False
    print('a' in y)
    
    
    Here, 'H' is in x but 'hello' is not present in x (remember, Python is case sensitive). Similarly, 1 is key and 'a' is the value in dictionary y. Hence, 'a' in y returns False.
    

[Djangoo]

Everything is very nicely explained.

[tux1]

Some good information, thanks for sharing.

[Flash7475]

This is a pretty comprehensive review of operators and is very well laid out.