Use Python 3

Use Python 3.

Read PEP 20

python -m this, every now and again.

If there’s anything to emphasize here that directly influences day-to-day writing, they are:

  • Explicit is better than implicit
  • Flat is better than nested
  • Sparse is better than dense
  • If the implementation is hard to explain, it’s a bad idea

Write Docstrings

PEP257 specifies base Docstring conventions, however format is not-included. People usually choose between reST, Google style, and Numpydoc, the latter two being the most popular.

Write Examples and “Test” Them

doctest runs examples formatted like so in your Docstrings:

> factorial(5)

If the output of the > line equals to the following line, your example passes. It tests every line that has an expected literal result.

This makes sure you write up to date examples, in case your API changes.

Use Linters

flake8 is pyflakes, pycodestyle, and McCabe script in one. However, flake8 does not catch some import and object issues like pylint, but pylint can be slow.

So consider this:

  • For real-time linting, use flake8
  • For on-save linting, use pylint

Additionally, I like using pydocstyle for consistent looking Docstrings.

Is your project OSS? Do your teammates hate linters?

Use pre-commit hooks.

Commit your .pylintrc, enforce the use of pre-commit hooks for pylint, pydocstyle, and pycodestyle.

Package your Project

Learn how to use, and keep your abstract dependencies under its install_requires.

Required reading: vs requirements.txt

Use Pipfiles, forget requirements.txt, forget virtualenvs

Install pipenv and never look back. This will manage your venvs and your concrete dependencies.

Almost every time, you will have the following in your Pipfile:

"-e ." = "*"

Bonus reading: pipenv#209

Unit Test

Use pytest, tests folder in project root, avoid files in your tests folder.

This ensures your tests can be run against an installed version of your package, i.e. -e ..

Strive for 100% Test Coverage, pipenv install pytest-cov --dev.

Pick out Best Practices you like

But not everything is up for discussion, don’t be a heathen and choose tabs over spaces.

Things you have to learn

  1. Decorators
  2. Context Managers
  3. OOP Magic Methods
  4. List Comprehension
  5. Generators
  6. Iterables vs. Iterators vs. Generators