Python Chapter#3: Basic Python Operators

Ankur Kulhari

An operator is a construct which performs some operation: arithmetic or logical, on operands.

Operators in Python

Python has following operators:

  • Arithmetic Operators
  • Comparison/Relational Operators
  • Assignment Operators
  • Logical Operators
  • Bitwise Operators
  • Membership Operators
  • Identity Operators
Python Arithmetic Operators
Operator Description Example [x=33, y=10]
Addition (+) Binary addition operator which adds both operands. x+y=33+10=43
Subtraction (-) Binary operator which subtracts right hand operand from left hand operand. x–y=33-10=23
Multiplication (*) Two Operands are multiplied x*y=33*10=330
Division (/) Binary operator which divides left hand operand by right hand operand x/y=33/10=3.3
Modulus (%) Binary operator divides left hand operand by right hand operand and returns remainder 33%10=3
Exponent (**) Performs exponential (power) calculation on operators 33**10=> 33 to the power 10

Comparison/Relational Operators

Relational Operators return the relationship of operands.

Operator Description Example [x=33, y=10]
== If the values of two operands are equal, returns true otherwise false. (x==y) is false.
!= If values of two operands are not equal, returns true otherwise false.
> If the value of left operand is greater than the value of right operand, returns true otherwise false. (x>y) is true.
< If the value of left operand is less than the value of right operand, returns true otherwise false. (x<y) is false.
>= If the value of left operand is greater than or equal to the value of right operand, returns true otherwise false. (x>=y) is true.
<= If the value of left operand is less than or equal to the value of right operand, returns true otherwise false. (x<=y) is false.

Assignment Operators

Python supports composite assignment operators also.

Operator Description Example [x=33, y=10, z=5]
= Binary operator, assigns value of right side operand to left side operand z=x+y => z=33+10 => z=43
+= Binary operator, adds right and left operand and assign the result to left operand z+=y => z=z+y => z=5+10=15 => z=15
-= Binary operator, subtracts right operand from the left operand and assign the result to left operand z-=y => z=z-y => z=5-10=-5 => z=-5
*= Binary operator, multiplies right and left operand and assign the result to left operand z*=y => z=z*y => z=5*10=50 => z=50
/= Binary operator, divides left operand with the right operand and assign the result to left operand z/=y => z=z/y => z=5/10=0.5 => z=0.5
%= Binary operator, devides left operand with right operand and assign remainder to left operand z%=y => z=z%y => z=5%10=5 => z=5
**= Binary operator, assign the result of left operand to the power right operand to left operand z**=y => z=z**y => z=5**10

Bitwise Operators

Bitwise operators operate on binary operands bit by bit.
We consider x=33, y=10 for all the examples in the below table. First of all x and y are converted to binary as:
x=100001, y=001010

Operator Description Example
Binary AND (&) 1&1=1, 1&0=0, 0&1=0, 0&0=0 (x&y)=>33&10=0
Binary OR (|) 1|1=1, 1|0=1, 0|1=1, 0|0=0 (x|y)=>(33)|(10)=43(101011)
Binary XOR (^) It gives 1, if both operand’s bits are not same, otherwise gives 0 (x^y)=>(33)^(10)=43(101011)
Binary Negation (~) It is unary. also called as ones complement. Inverts a bit. (~x) = ~(33)=-34
Binary Left Shift (<<) The left operands value is moved left by the number of bits specified by the right operand. x<<2= (33<<2)=10000100=132
Binary Right Shift(>>) The left operands value is moved right by the number of bits specified by the right operand. x>>2=8 (001000)

Logical Operators

In python there are three logical operators available.

Operator Description Example
Logical AND (and) If both the operands are true/non-zero/false then condition becomes true. (2 and 1)=1, (3 and 0)=0, ((2==3) and 1)= (False and 1)= False
Logical OR (or) If any of the two operands are 1/non-zero/true then condition becomes true. (2 and 1)=1, (3 and 0)=1, ((2==3) and 1)= (False and 1)= 1
Logical NOT (not) reverse the logical state of its operand. not 0 = True, not 1 = False, not (2==3) = True

Python Operators Precedence

Operators from highest precedence to lowest, same precedence in a row:

Operator Description
** Exponentiation (power)
~, +, – Complement, unary plus and minus
*, /, % Multiply, divide, modulo
+, – Addition and subtraction
>>, << Right and left bitwise shift
& Bitwise ‘AND’

^, | Bitwise XOR and OR
<=, <, >, >= Comparison operators
==, != Equality operators
=, %=, /=, -=, +=, *=, **= Assignment operators
is is not Identity operators

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