Python Tricks: The Book

I want to make it clear that calling the parameters args and kwargs is simply a naming convention. The previous example would work just as well if you called them *parms and **argv. The actual syntax is just the asterisk (*) or double asterisk (**), respectively.

Besides its use as a temporary variable, “_” is a special variable in most Python REPLs that represents the result of the last expression evaluated by the interpreter.

“double underscore” to “dunder.”

single trailing underscore (postfix) is used by convention to avoid naming conflicts with Python keywords. This convention is defined and explained in PEP 8.

Single underscores are a Python naming convention that indicates a name is meant for internal use. It is generally not enforced by the Python interpreter and is only meant as a hint to the programmer.

single underscore prefix has a meaning by convention only.

In Python, you can place a comma after every item in a list, dict, or set constant, including the last item

Don’t Use Asserts for Data Validation