Variable in Python

A variable can have a short name (like x and y) or a more descriptive name (age, carname, 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)
• A variable name cannot be any of the Python keywords.

Multi Words Variable Names

Variable names with more than one word can be difficult to read.

There are several techniques you can use to make them more readable:

Camel Case

Each word, except the first, starts with a capital letter:

myVariableName = "John"

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Pascal Case

Each word starts with a capital letter:

MyVariableName = "John"

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Snake Case

Each word is separated by an underscore character:

my_variable_name = "John"

Code :

legal_variable_names.py

Code :

variables_1.py

Code :

variables_2.py

Code :

variables_3.py

Code :

variables_4.py

Code :

variables_5.py

Code :

variables_6.py

Many Values to Multiple Variables

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

Code :

variables_7.py

One Value to Multiple Variables

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

Code :

variables_8.py

Unpack a Collection

If you have a collection of values in a list, tuple etc. Python allows you to extract the values into variables. This is called unpacking.

Code :

variables_9.py