Python Operators

 

Python Operators

 

Other than Keywords, Data Constants and Variables in any Programming Language, we can use few symbols or special characters called as Operators. Operators in general are used to perform certain operations on values and variables. These are standard symbols used for the purpose of logical and arithmetic operations. We will look into different types of operators available in Python. Every Operator takes on 2 or more Operands.

 

Operators: are the special symbols . Eg: +,-,*,/,=,etc.

 

Operand: It is the value on which the operator is applied with.

 

for Example

print(10+5)

This adds the 2 values 10 and 5 and displays the Result as 15.

 

Python classifies the operators in the following groups:

 

1.           Arithmetic operators

2.           Assignment operators

3.           comparison operators

4.           Logical operators

5.           Identity operators

6.           Membership operators

7.           Bitwise operators

8.           Special operators

 

 

Arithmetic Operators

 

Arithmetic operators are used with Numeric values to perform common Mathematical Operations:

 

Operator	Name	Usage Example
+	Addition	x+y
-	Subtraction	x-y
*	Multiplication	x*y
/	Division	x/y
%	Modulus	x%y
**	Exponentiation	x**y
//	Floor division	x//y

 

 

Operator  Precedence:

 

As in Mathematics , these Operators when occurring in an Expression, the evaluation is totally based on Operator precedence, which is as below.

 

·      P- Parentheses

·      E- Exponentiation

·      M- Multiplication (Multiplication and division have the same precedence)

·      D- Division

·      A- Addition (Addition and Subtraction have the same precedence)

·      S- Subtraction

 

The modulus operator helps us to extract the last digits of a number . i.e. the remainder part of a Division. For example:

 

x % 10   -> yields the last digits

x % 100 -> yield last two digits

 

Example : Arithmetic Operators in Python

 

This following example illustrates the usage syntax of the Arithmetic Operators.

 

a=9

b=4

#Addition of numbers

add=a+b

print(add)

 

Output:  13

 

#Subtraction of numbers

 

sub=a-b

print(sub)

 

Output:  5

 

#Multiplication of number

 

mul=a*b

print(mul)

 

Output: 36

 

#Division (float) of number

 

div1=a/b

print(div1)

 

 

Output: 2.25

 

#Division (floor) of number

 

div2=a//b

print(div2)

 

Output:  2

 

#Modulo of both number

 

mod=a % b

print(mod)

 

Output:  1

 

#Power

 

p=a**b

print(p)

 

Output:  6561

 

Assignment Operators

 

Assignment operators are used to assign values to variables. These Operators are used in Assignment Statements. In Python we have multiple type of Assignment Operators, they are

 

Operator	Example	Same As
=	x=5	x=5
+=	x+=3	x=x+3
-=	x-=3	x=x-3
*=	x*=3	x=x*3
/=	x/=3	x=x/3
%=	x%=3	x=x%3
//=	x//=3	x=x//3
**=	x**=3	x=x**3
&=	x&=3	x=x&3
|=	x|=3	x=x|3
^=	x^=3	x=x^3

 

#Examples of Assignment Operators

 

 

#Assign value

a=10

#Assign a variable

b=a

print(b)

 

Output:  10

 

#Add and assign value

b+=a

print(b)

 

Output: 20

 

#Subtract and assign value

 

b-=a

print(b)

 

Output: 10

 

#Multiply and assign

 

b*=a

print(b)

 

Output: 100

 

#bitwise left shift operator

 

b<<=a

 

Output:  102400

 

Comparison Operators

 

Comparison operators are used to compare two values, Mostly used in condition Checking of Control Statements. The Return value is Boolean.

 

Operator	Name	Example
==	Equal	x==y
!=	Not Equal	x!=y
>	Greater than	x>y
<	Less than	x<y
>=	Greater than or equal to	x>=y
<=	Less than or equal to	x<=y

 

Note:  = is an assignment operator and ==comparison operator.

 

#Example of Relational Operators

 

a=13

b=33

#a>b is False

print(a>b)

 

Output:  False

 

#a<b is True

print(a<b)

 

Output: True

 

#a==b is False

print(a==b)

 

Output: False

 

#a!=b is True

print(a!=b)

 

Output: True

 

#a>=b is False

print(a>=b)

 

Output:  False

 

#a<=b is True

print(a<=b)

 

Output: True

 

Logical Operators

 

Logical operators are used to combine 2 or more Conditional statements or Relational Expressions. Since the Operands are Boolean, the return value is always Boolean only.

 

 

 

#Examples of Logical Operator

 

a=True

b=False

 

#Print a and b is False

print(a and b)

 

Output: False

 

#Print a or b is True

print(a or b)

 

Output: True

 

#Print not a is False

print(not a)

 

Output: False

 

Identity Operators

 

Identity Operators are used to compare the objects, The comparison is not for whether they are equal, but for whether they are actually the same object, with the same memory location. In python only one instance of any object is created irrespective of multiple variables has the same value assigned to them , and that will be available till the end of the program or object being destroyed. Any variable which is assigned this value will share the same object only.

 

Operator	Description	Example
is not	Returns True if both variables are the same object	x is y
is not	Returns True if both variables are not the same object	x is not y

 

#Example: Identity Operator

 

a=10

b=20

c=a

print(a is not b)

 

Output: True

 

print(a is c)

 

Output: True

 

Membership operators

 

Membership operators are used to test if a value is present in a sequence object or not, These operators in Python are normally used with sequence Data Classes like List, Tuple, Set, Dictionary etc.,.

 

Operator	Description	Example
in	Returns True if a sequence with the specified value is present in the object	x in y
not in	Returns True if a sequence with the specified value is not present in the object.	x not in y

 

#Example: Membership Operator

 

#Python program to illustrate not 'in' operator

 

x=24

y=20

list=[10,20,30,40,50]

if (x not in list):

        print("x is NOT present in given list")

       

else:

        print("X is present in given list")

if (y not in list):

        print("y is NOT present in given list")

       

else:

        print("y is present in given list")

 

Output

x is NOT present in given list

y is present in given list

 

Bitwise Operators

 

Bitwise operators are used to perform certain operations on Binary numbers. These Operators are not used in Application Programming, but are needed in System program development.

 

Operator	Name	Description
&	AND	Sets each bit to 1 if both bits are 1
|	OR	Sets each bit to 1 if one of two bits is 1
^	XOR	Sets each bit to 1 if only one of two bits is 1
~	NOT	Inverts all the  bits
<<	Zero fill left shift	Shift left by pushing zeros in from the right and let the leftmost bits fall off.
>>	Signed Right shift	Shift right by pushing copies of the leftmost bit in from the left, and let the rightmost bits fall off.

 

When we use these Operators, the Numeric operands are converted to its binary form and the Operation is performed.

 

#Examples of Bitwise operators

 

a=10             00001010

b=4               00000100

#Print bitwise AND operation

print(a & b)

 

Output:  2

 

#Print bitwise OR operation

print(a | b)

 

Output: 11

 

#Print bitwise NOT operation

print(~a)

 

Output: -11

 

#Print bitwise XOR operation

print(a ^ b)

 

Output: 14

 

#Print bitwise right shift operation

 

print(a>>2)

 

Output: 2

 

#Print bitwise left shift operation

 

print(a<<2)

 

Output: 40