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Operator

Operators are the constructs which can manipulate the value of operands.

Consider the expression 4 + 5 = 9. Here, 4 and 5 are called operands and + is called operator.


Types of Operator

Python language supports the following types of operators.


  • Arithmetic Operators
  • Comparison (Relational) Operators
  • Assignment Operators
  • Logical Operators/2
  • Bitwise Operators
  • Membership OperatorsS
  • Identity Operators

Let us have a look on all operators one by one.


Python Arithmetic Operators


Assume variable a holds 10 and variable b holds 20, then −


Operator
Description
Example

+ Addition

Adds values on either side of the operator.

a + b = 30

- Subtraction

Subtracts right hand operand from left hand operand.

a – b = -10

* Multiplication

Multiplies values on either side of the operator

a * b = 200

/ Division

Divides left hand operand by right hand operand

b / a = 2

% Modulus

Divides left hand operand by right hand operand and returns remainder

b % a = 0

** Exponent

Performs exponential (power) calculation on operators

a**b =10 to the power 20

// 

Floor Division - The division of operands where the result is the quotient in which the digits after the decimal point are removed. But if one of the operands is negative, the result is floored, i.e., rounded away from zero (towards negative infinity) −

9//2 = 4 and 9.0//2.0 = 4.0, -11//3 = -4, -11.0//3 = -4.0


Python Comparison Operators


These operators compare the values on either sides of them and decide the relation among them. They are also called Relational operators.


Assume variable a holds 10 and variable b holds 20, then −


Operator
Description
Example

==

If the values of two operands are equal, then the condition becomes true.

(a == b) is not true.

!=

If values of two operands are not equal, then condition becomes true..

(a != b) is true.

<>

If values of two operands are not equal, then condition becomes true.

(a <> b) is true. This is similar to != operator.

>

If the value of left operand is greater than the value of right operand, then condition becomes true.

(a > b) is not true.

<

If the value of left operand is less than the value of right operand, then condition becomes true.

(a < b) is true.

>=

If the value of left operand is greater than or equal to the value of right operand, then condition becomes true.

(a >= b) is not true.

<=

If the value of left operand is less than or equal to the value of right operand, then condition becomes true.

(a <= b) is true.


Python Assignment Operators


Assume variable a holds 10 and variable b holds 20, then −


Operator
Description
Example

=

Assigns values from right side operands to left side operand.

c = a + b assigns value of a + b into c

+= Add AND

It adds right operand to the left operand and assign the result to left operand

c += a is equivalent to c = c + a

-= Subtract AND

It subtracts right operand from the left operand and assign the result to left operand

c -= a is equivalent to c = c - a

*= Multiply AND

It multiplies right operand with the left operand and assign the result to left operand

c *= a is equivalent to c = c * a

/= Divide AND

It divides left operand with the right operand and assign the result to left operand

c /= a is equivalent to c = c / a

%= Modulus AND

It takes modulus using two operands and assign the result to left operand

c %= a is equivalent to c = c % a

**= Exponent AND

Performs exponential (power) calculation on operators and assign value to the left operand

c **= a is equivalent to c = c ** a

//= Floor Division

It performs floor division on operators and assign value to the left operand

c //= a is equivalent to c = c // a


Python Bitwise Operators


Bitwise operator works on bits and performs bit by bit operation. Assume if a = 60; and b = 13; Now in the binary format their values will be 0011 1100 and 0000 1101 respectively. Following table lists out the bitwise operators supported by Python language with an example each in those, we use the above two variables (a and b) as operands −


a = 0011 1100

b = 0000 1101

-----------------

a&b = 0000 1100

a|b = 0011 1101

a^b = 0011 0001

~a = 1100 0011


There are following Bitwise operators supported by Python language


Operator
Description
Example

& Binary AND

Operator copies a bit to the result if it exists in both operands

(a & b) (means 0000 1100)

| Binary OR

It copies a bit if it exists in either operand.

(a | b) = 61 (means 0011 1101)

^ Binary XOR

It copies the bit if it is set in one operand but not both.

(a ^ b) = 49 (means 0011 0001)

~ Binary Ones Complement

It is unary and has the effect of 'flipping' bits.

(~a ) = -61 (means 1100 0011 in 2's complement form due to a signed binary number.

<< Binary Left Shift

The left operands value is moved left by the number of bits specified by the right operand.

a << 2 = 240 (means 1111 0000)

>> Binary Right Shift

The left operands value is moved right by the number of bits specified by the right operand.

a >> 2 = 15 (means 0000 1111)


Python Logical Operators


There are following logical operators supported by Python language. Assume variable a holds 10 and variable b holds 20 then


Operator
Description
Example

and Logical AND

If both the operands are true then condition becomes true.

(a and b) is true.

or Logical OR

If any of the two operands are non-zero then condition becomes true.

(a or b) is true.

not Logical NOT

Used to reverse the logical state of its operand.

Not(a and b) is false.


Python Membership Operators


Python’s membership operators test for membership in a sequence, such as strings, lists, or tuples. There are two membership operators as explained below −


Operator
Description
Example

in

Evaluates to true if it finds a variable in the specified sequence and false otherwise.

x in y, here in results in a 1 if x is a member of sequence y.

not in

Evaluates to true if it does not finds a variable in the specified sequence and false otherwise.

x not in y, here not in results in a 1 if x is not a member of sequence y.


Python Identity Operators


Identity operators compare the memory locations of two objects. There are two Identity operators explained below −


Operator
Description
Example

is

Evaluates to true if the variables on either side of the operator point to the same object and false otherwise.

x is y, here is results in 1 if id(x) equals id(y).

is not

Evaluates to false if the variables on either side of the operator point to the same object and true otherwise.

x is not y, here is not results in 1 if id(x) is not equal to id(y).


Python Operators Precedence


The following table lists all operators from highest precedence to lowest.


Sr.No.
Operator & Description
1
**    
Exponentiation (raise to the power)
2
~ + -    
Complement, unary plus and minus (method names for the last two are +@ and -@)
3
* / % //    
Multiply, divide, modulo and floor division
4
+ -    
Addition and subtraction
5
>> <<     
Right and left bitwise shift
6
&     
Bitwise 'AND'
7
^ |     
Bitwise exclusive `OR' and regular `OR'
8
<= < > >=     
Comparison operators
9
<> == !=     
Equality operators
10
= %= /= //= -= += *= **=     
Assignment operators
11
is is not    
Identity operators
12
in not in    
Membership operators
13
not or and    
Logical operators



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