naming rules of variables in python

 In Python, variable names must follow certain naming rules and conventions. Here are some of the basic rules for naming variables in Python:

1. Variable names must begin with a letter or underscore.
2. Variable names can contain letters, numbers, and underscores.
3. Variable names are case sensitive, so x and X are two different variables.
4. Variable names should be descriptive and not too long.
5. Variable names should not use built-in keywords or function names, such as print or if.

Here are some examples of valid and invalid variable names in Python:

Valid variable names:

python
x 
_y 
x_1 
my_variable

Invalid variable names:

python
1x   # cannot start with a number 
my-variable  # cannot contain hyphens
my variable  # cannot contain spaces 
print  # cannot use built-in function names

It is also a convention in Python to use lowercase variable names, with underscores separating words in multi-word variable names. This makes the code more readable and easier to understand. For example:

python
my_variable_name