How can I check for which command is run in setup.py?

Question

I would like to know how to make some code in setup.py conditional on which command (e.g. install or upload) was run.

Specifically, I'd like to have:

1. An easy way to add "hacks" such as ignoring a particular file in install, but no other commands.
2. A recommended/canonical way to add hooks such as running tests before installing.

I have tried reading the distutils documentation, but it's pretty sparse on details – the distutils.command[.foo] modules are completely undocumented.

For the first point I can check sys.argv like mentioned in this question, but that doesn't work when multiple commands are run, like:

python setup.py sdist bdist upload

so it isn't applicable in general.

Answer 1

You can override the command instead:

from distutils.command.install import install
from distutils.core import setup

def run_file(path):
    with open(path, 'r') as f:
        exec(f.read())

class myinstall(install): # subclass distutils's install command
    def finalize_options(self): # called after option parsing
        # call base class function
        install.finalize_options(self)
        # super won't work because distutils under Python 2 uses old-style classes
        # ignore a module
        self.distribution.py_modules.remove('mymodule')
    def run(self): # called to run a command
        # run tests first
        run_file('path/to/test.py')
        # ^ remember to make sure the module is in sys.path
        # run the real commands
        install.run(self)

setup(
    name='abc',
    py_modules=['mymodule'],
    cmdclass={'install': myinstall}
    # ^ override the install command
)