python-devtools

python-devtools (imported as devtools) provides a smarter replacement for Python’s print when debugging. Its debug() function prints the file, line, and variable name alongside the value, applies rich syntax-highlighted pretty formatting, and detects the type of each expression, turning ad-hoc print debugging into something genuinely readable.

Beyond debug(), the package bundles a suite of developer utilities: a pretty-printer, an execution timer, ANSI color helpers, and a pytest plugin featuring insert_assert for automatically generating test assertions. It is fully type-annotated and works across supported Python 3 versions.

What You Get

• A debug() function that prints file, line, variable name, value, and type
• Rich, syntax-highlighted pretty formatting of nested and complex data structures
• A Timer utility for quick execution timing during development
• A pytest plugin with insert_assert to auto-generate assertions from runtime values
• Full type annotations (py.typed) and a small, focused dependency set

Common Use Cases

• Replacing scattered print statements with informative, self-labeling debug output
• Pretty-printing deeply nested dictionaries, lists, and objects while exploring data
• Auto-generating and updating test assertions in pytest via insert_assert

Under The Hood

Architecture - The devtools package centers on debug.py, which builds a Debug object that inspects the calling frame using executing and asttokens to recover the exact source expression passed to debug(). Formatting is handled by prettier.py (with Pygments-based highlighting via ansi.py), timing by timer.py, and pytest integration by pytest_plugin.py; a __main__.py allows module-level invocation.

Tech Stack - Pure Python (>=3.7), built with hatchling, depending on executing (for locating the call expression), asttokens (AST source mapping), and Pygments (syntax highlighting). Documentation is built with MkDocs.

Code Quality - The project is production-stable with a comprehensive pytest suite (test_main.py, test_prettier.py, test_expr_render.py, test_insert_assert.py, and more), codecov coverage tracking, and CI on GitHub Actions. The code is fully typed and ships py.typed.

API Design - The headline API is a single, memorable debug() call that just works as a drop-in for print, with no configuration required. Additional tools (Timer, the pytest plugin) follow small, discoverable interfaces, and the hosted documentation site keeps the learning curve minimal.