What is Variable in Python

A variable is a label for a location in memory that can be used to hold a value. Unlike other programming languages, python is not strictly typed, i.e. there is no need to declare variables or declare their type before using them.

Rules for creating variables in Python:

• The variable must start with a letter or underscore character.
• The variable name cannot start with a number.
• Only alpha-numeric characters and underscores (A-z, 0-9, and _ ) must be in a variable name.
• Variable names are case-sensitive (name, Name, and NAME are three different variables).
• The reserved words(keywords) cannot be used to name the variable.

Example:

a = 5
 
b = 'PYTHON'

c = 3.09
print(a)
print(b)
print(c)

Output:

5
PYTHON
3.09

A variable once declared can be re-declared in Python. But the previous data is lost.

Example:

a = 5

print("Before redeclaring: ", a)

a  = 15.43

print("After redeclaring: ", a)

Output:

Before redeclaring:  5
After redeclaring:  15.43