Want faster, cleaner Python without wasting time? These tips focus on habits and tools that pay off immediately. You’ll get concrete shortcuts, performance moves, and simple tooling advice that you can apply to real projects today.
Use f-strings for readable string formatting: f"{name} took {time:.2f}s" beats older % or format methods. Prefer list comprehensions and generator expressions when they simplify the code—use generators for large streams to save memory. When you need small immutable records, reach for dataclasses: @dataclass keeps init and repr tidy and avoids boilerplate.
Type hints aren’t just for style. Add basic typing to function signatures so editors and tools warn you about mismatches. Run mypy or Pyright in CI to catch issues before they reach production. For runtime checks, consider pydantic for data validation in APIs—it's explicit and saves debugging time later.
Cache expensive calls with functools.lru_cache. A single decorator can cut repeated database or CPU-heavy calls dramatically. For one-off heavy loops, use built-in functions like map, sum, any, all and avoid writing extra Python loops—C-backed functions are faster.
Use a consistent formatter and linter: black plus flake8 (or ruff) keeps style off your plate and finds obvious issues. Configure pre-commit so formatting and basic checks run before commits. You’ll spend less time on style debates and more on logic.
Test small and fast. Pytest makes unit tests readable; use parametrized tests to cover many cases with little code. Add a few integration tests for key flows. Run coverage to find untested edge cases, but don’t obsess—target meaningful coverage, not a number.
When debugging, start with logging, not print. Structured logging (with levels and context) helps you reproduce issues later. For live debugging, pdb or the debugger in VS Code can inspect state without guesswork. Use pytest --pdb to drop into a failing test quickly.
Profile before you optimize. Use cProfile or pyinstrument to find real bottlenecks. Often a small hot spot—like an unnecessary list copy—causes most of the slowdown. For numeric work, use numpy or vectorized ops rather than Python loops.
Keep environments clean: venv or virtualenv for projects, and pin dependencies with a lockfile (pip-tools, poetry, or pipx where appropriate). Reproducible installs avoid the "works on my machine" trap.
Final practical habit: read other people’s code. Open-source projects teach idioms and patterns you won’t see in tutorials. Pick one well-written repo and follow how they structure tests, handle errors, and document functions. Small, steady improvements to your workflow beat one-off hacks every time.