Python3

Python 3 Best Practices

Project Structure & Packaging

• Prefer pyproject.toml for project metadata, build system configuration, and dependencies. Use requirements.txt as a fallback or for specific environment pinning.
• Use a src-layout: Place main application code inside a src/your_package_name/ directory.
• Place tests in a tests/ directory parallel to src/.
• Keep configuration separate (e.g., in environment variables, .env files loaded via appropriate libraries, or dedicated config files/modules).
• Structure code logically by feature or domain within the src directory.

Code Style & Formatting

• Adhere strictly to PEP 8.
• Use an automated code formatter for consistency.
• Use an import sorting tool for consistent import ordering.
• Use a linter (identifying style issues, potential bugs, complexity).
• Configure these tools appropriately (e.g., in pyproject.toml).
• Naming Conventions (PEP 8):
  • snake_case for functions, methods, variables, and modules.
  • PascalCase (or CapWords) for classes.
  • UPPER_SNAKE_CASE for constants.
  • Leading underscore (_) for internal/protected attributes/methods.
  • Double leading underscore (__) for name mangling (use sparingly).

Language Features & Idioms

• Use f-strings for string formatting (f"Value is {variable}"). Avoid older formatting methods.
• Use context managers (with statement) for resources that need cleanup (files, network connections, locks, database connections). Implement __enter__ and __exit__ for custom context managers or use contextlib.
• Use list/dict/set comprehensions and generator expressions for concise and efficient creation of sequences.
• Leverage built-in functions and modules (e.g., itertools, collections, functools) where appropriate.
• Prefer exceptions for error handling over returning error codes or None for exceptional situations.
• Use pathlib for object-oriented filesystem path manipulation instead of os.path.
• Use enum.Enum for enumerations.
• Use dataclasses (or similar libraries) for classes primarily holding data.