Python Cheat Sheet

Pyenv

My pyenv install guide

Iterator vs. Iterable

iterable

• An object capable of returning its members one at a time.
• Provides an __iter__() method.

iterator

• An object representing a stream of data.
• Provides __iter__() and __next__() methods.
• collections.abc.Iterator inherits from collections.abc.Iterable.

Count the number of items in an iterable

from collections import deque
from itertools import count

def len_iter(iterable):
    deque(maxlen=0).extend(zip(iterable, ctr := count()))
    return next(ctr)

Source: ShadowRanger on StackOverflow (CC BY-SA 4.0)

Minimal pyproject.toml

Static version

[build-system]
requires = ["setuptools"]
build-backend = "setuptools.build_meta"

[project]
name = "project-name"
version = "0.1.0"

Dynamic version

[build-system]
requires = ["setuptools", "setuptools-scm[simple]"]
build-backend = "setuptools.build_meta"

[project]
name = "project-name"
dynamic = ["version"]

Sources

• Writing your pyproject.toml
• Setuptools quickstart

Minimal .flake8 config for Black

[flake8]
max-line-length = 88
extend-ignore = E203,E701

Source: Using Black with other tools