Makefiles are typically used for C and C++ projects to build source code but they can be useful for Python projects too. A Makefile is just a text file used by the GNU Make tool to run commands. For a Python project, these commands can run unit tests, format your code, or publish a package to PyPI.
A rule in a Makefile is structured as shown below. A target is the name of a file or the name of an action to carry out. A dependency or prerequisite is a file that is used as input to create the target (this is optional). The command or recipe is an action that Make carries out. Note that commands are indented with a tab (not spaces).
target: dependencies ...
commands
...
The content of a simple Makefile that can be used for a Python project is shown below. Use the make command in the terminal to execute a rule in the file. For example, run make check to perform the linter and formatter checks with the ruff tool, run make test to use pytest, run make clean to remove the cache directories. The all target uses the check, test, and clean targets as dependencies. When you execute make all, the check, test, and clean rules will be run in that order.
A Makefile example for Python is available in the pythonic/python-projects/makefile-project directory on GitHub. The file structure for the example is shown here along with the contents of the Makefile. Settings for the ruff linter are in the pyproject.toml.
# Contents of the Makefile
help:
@printf "\nCommands:\n"
@printf "\033[32mcheck\033[0m ruff linter and formatter checks\n"
@printf "\033[32mclean\033[0m delete cache directories\n"
@printf "\033[32mtest\033[0m run unit tests with pytest\n"
@printf "\033[32mall\033[0m run check, test, and clean rules\n"
check:
ruff check .
ruff format --check .
clean:
rm -rf .ruff_cache
rm -rf .pytest_cache
rm -rf __pycache__
test:
pytest --verbose --cache-clear
all: check test clean
Running make check in the makefile-project directory should output the linter warnings shown below. Running make test should display a failed pytest and running make clean will remove the cache directories created by ruff and pytest.
$ make check
ruff check .
main.py:1:1: D100 Missing docstring in public module
main.py:1:17: F401 [*] `numpy` imported but unused
main.py:11:5: D400 First line should end with a period
main.py:11:5: D401 First line of docstring should be in imperative mood: "here"
test_adder.py:1:1: D100 Missing docstring in public module
test_adder.py:3:5: D103 Missing docstring in public function
Found 6 errors.
[*] 1 fixable with the `--fix` option (1 hidden fix can be enabled with the `--unsafe-fixes` option).
make: *** [check] Error 1
Run make or make help to print the help information to the screen (shown below). When make is run without specifying a target, it executes the first target in the Makefile; which is the help target in this example.
Commands:
check ruff linter and formatter checks
clean delete cache directories
test run unit tests with pytest
all run check, test, and clean rules
See the GNU Make website for more information about Makefiles and the Make tool. Some Python projects that use a Makefile are FastUI and LEAP.
