Can Pip install dependencies not specified in setup.py at install time?

Question

I\'d like pip to install a dependency that I have on GitHub when the user issues the command to install the original software, also from source on GitHub. Neither of these p

Answer 1

Here's a small script I used to generate install_requires and dependency_links from a requirements file.

import os
import re

def which(program):
    """
    Detect whether or not a program is installed.
    Thanks to http://stackoverflow.com/a/377028/70191
    """
    def is_exe(fpath):
        return os.path.exists(fpath) and os.access(fpath, os.X_OK)

    fpath, _ = os.path.split(program)
    if fpath:
        if is_exe(program):
            return program
    else:
        for path in os.environ['PATH'].split(os.pathsep):
            exe_file = os.path.join(path, program)
            if is_exe(exe_file):
                return exe_file

    return None

EDITABLE_REQUIREMENT = re.compile(r'^-e (?P(?Pgit|svn|hg|bzr).+#egg=(?P.+)-(?P\d(?:\.\d)*))$')

install_requires = []
dependency_links = []

for requirement in (l.strip() for l in open('requirements')):
    match = EDITABLE_REQUIREMENT.match(requirement)
    if match:
        assert which(match.group('vcs')) is not None, \
            "VCS '%(vcs)s' must be installed in order to install %(link)s" % match.groupdict()
        install_requires.append("%(package)s==%(version)s" % match.groupdict())
        dependency_links.append(match.group('link'))
    else:
        install_requires.append(requirement)