Python - Variable Names

Variable Names

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.

Legal variable names:

myvar = "John"
my_var = "John"
_my_var = "John"
myVar = "John"
MYVAR = "John"
myvar2 = "John"

Illegal variable names:

2myvar = "John"
my-var = "John"
my var = "John"

Remember that variable names are case-sensitive

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

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

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

myVariableName = "John"

Each word starts with a capital letter:

MyVariableName = "John"

Each word is separated by an underscore character:

my_variable_name = "John"