Reference requirements.txt for the install_requires kwarg in setuptools setup.py file

Question

I have a requirements.txt file that I'm using with Travis-CI. It seems silly to duplicate the requirements in both requirements.txt and setup.py, so I was hoping to pass a file handle to the install_requires kwarg in setuptools.setup.

Is this possible? If so, how should I go about doing it?

Here is my requirements.txt file:

guessit>=0.5.2 tvdb_api>=1.8.2 hachoir-metadata>=1.3.3 hachoir-core>=1.3.3 hachoir-parser>=1.3.4 

Answer 1

You can flip it around and list the dependencies in setup.py and have a single character — a dot . — in requirements.txt instead.

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Alternatively, even if not advised, it is still possible to parse the requirements.txt file (if it doesn't refer any external requirements by URL) with the following hack (tested with pip 9.0.1):

install_reqs = parse_requirements('requirements.txt', session='hack') 

This doesn't filter environment markers though.

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In old versions of pip, more specifically older than 6.0, there is a public API that can be used to achieve this. A requirement file can contain comments (#) and can include some other files (--requirement or -r). Thus, if you really want to parse a requirements.txt you can use the pip parser:

from pip.req import parse_requirements  # parse_requirements() returns generator of pip.req.InstallRequirement objects install_reqs = parse_requirements(<requirements_path>)  # reqs is a list of requirement # e.g. ['django==1.5.1', 'mezzanine==1.4.6'] reqs = [str(ir.req) for ir in install_reqs]  setup(     ...     install_requires=reqs )