分类： Python3

positional argument
keyword argument

The difference between *args and **kwargs, both are variadic arguments in python:

*args represents any number of unnamed arguments, which is essentially a tuple

**kwargs means keyword arguments, which is essentially a dict

When using both *args and **kwargs, the *args argument must be listed before **kwargs.

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Source: Python Crash Course, 2nd Edition A Hands-On:

Note: You’ll often see the generic parameter name *args, which collects arbitrary positional
arguments like this.

Note: You’ll often see the parameter name **kwargs used to collect non-specific keyword
arguments.

The Zen of Python is a collection of 19 “guiding principles” for writing computer programs that influence the design of the Python programming language. Software engineer Tim Peters wrote this set of principles and posted it on the Python mailing list in 1999. Peters’s list left open a 20th principle “for Guido to fill in”, referring to Guido van Rossum, the original author of the Python language. The vacancy for a 20th principle has not been filled.

Peters’s Zen of Python was included as entry number 20 in the language’s official Python Enhancement Proposals and was released into the public domain. It is also included as an Easter egg in the Python interpreter, where it can be displayed by entering import this.

Principles

The principles are listed as follows:

• Beautiful is better than ugly.
• Explicit is better than implicit.
• Simple is better than complex.
• Complex is better than complicated.
• Flat is better than nested.
• Sparse is better than dense.
• Readability counts.
• Special cases aren’t special enough to break the rules.
• Although practicality beats purity.
• Errors should never pass silently.
• Unless explicitly silenced.
• In the face of ambiguity, refuse the temptation to guess.
• There should be one– and preferably only one –obvious way to do it.
• Although that way may not be obvious at first unless you’re Dutch.
• Now is better than never.
• Although never is often better than right now.
• If the implementation is hard to explain, it’s a bad idea.
• If the implementation is easy to explain, it may be a good idea.
• Namespaces are one honking great idea – let’s do more of those!