How not to write Python code

Abstraction: Python anti-patterns and idiomatic best practices to avoid common mistakes

Key points:

• Use the standard library ("batteries included") before adding dependencies; e.g. use BaseHTTPServer instead of Twisted for simple HTTP
• Avoid from foo import * (pollutes namespace); prefer explicit imports or import foo
• Use Pythonic patterns — e.g. dicts + function objects to emulate switch/case, since Python has none
• Write docstrings and tests (unittest or doctest) during development, not after; use exception subclasses not bare returns for errors
• Use built-ins like isinstance(arg, (TypeA, TypeB)), getattr/setattr, and avoid arg.__class__ == MyClass
• Use code metrics tools (e.g. PyLint) and interactive shells (iPython) during development; avoid messing with sys.path

Connections: Pylint · Ipython · Python · Software Engineering · Code Quality

Source: http://eikke.com/how-not-to-write-python-code/