Python Essentials

Organizing Python code

Python programs should be beautiful. To that end, the language has few syntactic overheads; we should be able to write short scripts without unpleasant boilerplate. The principle is sometimes articulated as Simple things should be simple. The "Hello World" script really is a single line of code that uses the print() function.

A more complex file will generally have a few major sections:

• A !# line, often #!/usr/bin/env python3.
• A docstring comment explaining what the module does.
• The function or class definitions. We often group multiple functions and classes into a single module. The module is the proper unit of reuse in Python.
• If the module can be run as a main script, we'll include an if __name__ == "__main__": section that ...