How to obtain arguments passed to setup.py from pip with '--install-option'?

Question

I am using pip 1.4.1, attempting to install a package from a local path, for example:

pip install /path/to/my/local/package

This does what

Answer 1

For consistency, you can add an option to both setup.py install and setup.py develop (aka pip install -e): (building off Ronen Botzer's answer)

from setuptools import setup
from setuptools.command.install import install
from setuptools.command.develop import develop


class CommandMixin(object):
    user_options = [
        ('someopt', None, 'a flag option'),
        ('someval=', None, 'an option that takes a value')
    ]

    def initialize_options(self):
        super().initialize_options()
        # Initialize options
        self.someopt = None
        self.someval = 0

    def finalize_options(self):
        # Validate options
        if self.someval < 0:
            raise ValueError("Illegal someval!")
        super().finalize_options()

    def run(self):
        # Use options
        global someopt
        someopt = self.someopt # will be 1 or None

        super().run()

class InstallCommand(CommandMixin, install):
    user_options = getattr(install, 'user_options', []) + CommandMixin.user_options

class DevelopCommand(CommandMixin, develop):
    user_options = getattr(develop, 'user_options', []) + CommandMixin.user_options

setup(
    ...,
    cmdclass={
        'install': InstallCommand,
        'develop': DevelopCommand,
    }

Then you can pass options to pip like:

pip install --install-option="--someval=1" --install-option="--someopt" .

Or in develop mode:

pip install -e --install-option="--someval=1" .