Logical, Identity , Membership and Unary Operators in Python

                                                

1 Logical operator:

Python supports Three Logical Operators i.e. "Logical  AND (&&)","Logical  OR(||) ", "Logical NOT(!)" .As in case of arithmetic expression, the logical operator will execute from left to right .

Logical Operator are the operators which includes Logical operations that Manipulate Boolean Values 

Boolean Values are either True or False .

    
Logical AND (&&):

Logical  AND operator is used to check two conditions at the same time .If both conditions are True then the whole expression becomes true.

Logical OR(||):

Logical OR operator is used to execute two expressions at the same time with a relational operator .If one of the conditions is true then the whole expression becomes True. 

Logical NOT(!): 

The logical NOT operator takes a single value and just reverses that value . It means if the value is non zero then the NOT operator converts it into zero and for zero it will convert it to one .

Example :

x=4,y

y=!x

print(y)

Output _ 0(Zero)

Operator name	Description	Syntax
AND(&&)	True only when both expression are True	Exp1 and Exp2
OR(||)	True when any one of the expression is true	Exp1 or Exp2
NOT(!)	Reverse the value	not(a)

NOTE	Truth tables for logical and binary operators are the same .

Logical operators operate in an  alternate fashion . It means in Logical and if first expression is false then  compiler will not check for the second one on similar ground in OR operator if the first expression is true then it will not execute the second one .

 EXAMPLE : Program to illustrate concepts of logical operators  

                                                           

2 . Python Identity Operator :

 Identity operators are used to compare object and it will return true if the objects are same ,and               false if they are different .Identity operator compare Memory locations of two objects .

There are two Identity operators which Python supports i.e. " is " , " is not "

Operator name	Description	Example
is	Returns true if values on both sies of the operators points to the same object.false otherwise.	if a is b
is not	Return true if values on both sides of the operator points to different object , false otherwise	if a is not b

Example : To illustrate concept of Identity Operator 

                                                   

Python : Membership Operator:

Python supports two types of Membership operators .in and not in .These  operators, as the name suggest test for membership in a sequence such as string ,lists and sets (data types)

Operator name	Description
in	Returns true if the member is present in given sequence ,false otherwise
not in	Returns true if the member is not present in the given sequence ,false otherwise.

Example : To illustrate concept of  Membership Operator 

                                          

  Unary Operator :             

      Unary  operators are operate on a single Operand. Python supports       unary minus operator.

unary minus is totally different than the minus operator in arithmetic operators .When an operand is preceded by a minus sign the unary operator negates the value .In short if the number is positive then 

it gets converted into a negative number after applying this operator and wise versa. 

Example:

x=5

y=-(x)

print(y)

OUTPUT : -5       #Negative Number

      

NOTE	Python does not support postfix and prefix increment and decrement operators .