Naming conventions for Python code modules are a great help in keeping us efficient and helping us remember our original design. When we need to debug and fix a defect or add a new functionality, they are the first resources to look at.

On the other hand, naming Python variables is more of a free form. Python infers types, so we do not have to specify that a variable will be of type <list> (it might not be, or later in the code, it might become a different type).

A good idea for naming variables is to make them descriptive and it is also a good idea not to abbreviate too much.

If we wish to point out that a certain variable is designed to be of the <list> type, then it is much more intuitive to use the full word list instead of lst.

It is similar for number instead of num.

While it is a good idea to have very descriptive names for variables, sometimes that can get too long. In Apple's Objective-C language, some variable and function names are extreme: thisIsAMethodThatDoesThisAndThatAndAlsoThatIfYouPassInNIntegers:1:2:3