Variables and Operators in Python

VARIABLES

Creating variables

Variables are a container for storing the data values.

Unlike other programming, languages python has no command for declaring a variable.

A variable is created the moment you first assign the value to it.

Code:

x = 5

y = "john"

print(x)

print(y)  

Variables do not need to be declared with any particular type and can even change type after they have been set.

String variables can be declared either by using single or double quotes:

a = "John"

# is the same as

b = 'John'

Variable Names

A variable can have a short name (like x and y) or a more descriptive name (age, car_name, total_volume). Rules for Python variables:

• A variable name must start with a letter or the underscore character
• A variable name cannot start with a number
• A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )
• Variable names are case-sensitive (age, Age, and AGE are three different variables)

Note:- Variable names are case-sensitive.

Assign Value to Multiple Variables

Python allows you to assign values to multiple variables in one line:

x, y, z = "Oranges", "Apples", "Mango"

print(x)

print(y)

print(z)

And you can assign the same value to multiple variables in one line:

x = y = z = "Oranges"

print(x)

print(y)

print(z)

Python Arithmetic Operators

Arithmetic operators are used with numeric values to perform common mathematical operations:

Operators	Names	Example
(+)	Addition	x + y
(-)	Subtraction	x-y
(*)	Multiplication	x*y
(/)	Division	x/y
(%)	Modulus	x%y
(**)	Exponentiation	x**y
(//)	Floor Division	x//y

Python Assignment Operators

Assignment operators are used to assigning values to variables:

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
>>=	x >>= 3	x = x >> 3
<<=	x <<= 3	x = x << 3

Python Comparison Operators

Comparison operators are used to comparing two values

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

Python Logical Operators

Logical operators are used to combining conditional statements.

Operator	Description	Example
and	Returns True if both statements are true	x < 5 and x < 10
or	Returns True if one of the statements is true	x < 5 or x < 4
not	Reverse the result, returns False if the result is true	not(x < 5 and x < 10)

Python Identity Operators

Identity operators are used to comparing the objects, not if they are equal, but if they are actually the same object, with the same memory location.

Operator	Description	Example
is	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

Python Membership Operators

Membership operators are used to testing if a sequence is presented in an object.

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

Python Bitwise Operators

Bitwise operators are used to comparing (binary) numbers.

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

Bonus:

Real Python:- Python Basic Data Types

Real Python:- Test your Basic Data types skills, 

W3School:- W3School operators 

Sanfound:- Sanfoundry Test your skills with MCQs