python - setuptools and pip: choice of minimal and complete install

Question

We've made a library which depends on other libraries. But there are necessary (e.g. for server batch processing) and optional dependencies (e.g. for clients with GUI).

Is something like this possible:

pip install mylib.tar.gz  # automatically downloads and installs with the minimal set of dependencies

pip install mylib.tar.gz  --install-option="complete"  # automatically installs with all dependencies

I've found the extra_require flag, but how can I tell pip to use them? The setup.py looks like this:

from setuptools import setup

# ...

# Hard library depencencies:
requires = [
    "numpy>=1.4.1",
    "scipy>=0.7.2",
    "traits>=3.4.0"
]

# Soft library dependencies:
recommended = {
    "mpl": ["matplotlib>=0.99.3"],
    "bn": ["bottleneck>=0.6"]
}

# ...

# Installer parameters:
setup(
    name = "mylib",
    #...
    install_requires = requires,
    extras_require = recommended
)

Answer 1

You can install the packages in extras_require by appending the name of the recommended dependency in square brackets (i.e. [mpl] or [bn] in your case) to the package name in pip.

So to install 'mylib' with the additional requirements, you would call pip like this:

pip install 'mylib[mpl]'
pip install 'mylib[bn]'

This will first download and install the extra dependencies, and then mylib's core dependencies.

This is anologous to how you declare those dependencies with setuptools: http://pythonhosted.org/setuptools/setuptools.html#declaring-extras-optional-features-with-their-own-dependencies (see the install_requires value in the third example)