[Basic Grammar] Python Variables: Variable Names

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

 

For better understanding, please refer to the following example. 

 

Example 

Legal variable names:

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

Ilegal variable names: 

2myvar = "Kim"
my-var = "Kim"
my var = "Kim"

 

 

• Techniques to make it more readeable

• Camel Case 

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

myVariableName = "David"

• Pascal Case 

Each word starts with a capital letter:

MyVariableName = "John"

• Snake Case 

my_variable_name = "Berry"