Read Python dependencies from requirements file and strip off version numbers.

parse_requirements.py

def parse_requirements(requirements, ignore=('setuptools',)):
    """Read dependencies from file and strip off version numbers."""
    with open(requirements) as f:
        packages = set()
        for line in f:
            line = line.strip()
            if line.startswith(('#', '-r', '--')):
                continue
            if '#egg=' in line:
                pkg = line.split('#egg=')[1]
            else:
                pkg = line.split('==')[0]
            if pkg not in ignore:
                packages.add(pkg)
        return packages


if __name__ == '__main__':
    import sys
    print("\n".join(sorted(parse_requirements(
        sys.argv[1] if sys.argv[1:] else 'requirements.txt'))))

parse_requirements2.py

import re

def parse_requirements(requirements, ignore=('setuptools',)):
    """Read dependencies from file and strip off version numbers.

    Supports extra requirements and '>=' and '<=' version qualifiers.
    """
    with open(requirements) as f:
        packages = set()
        for line in f:
            line = line.strip()
            if not line or line.startswith(('#', '-r', '--')):
                continue

            # XXX: Ugly hack!
            extras = []
            def get_extras(match):
                extras.append(match.group(1))

            line = re.sub(r'\s*\[(.*?)\]', get_extras, line)

            if '#egg=' in line:
                line = line.split('#egg=')[1]

            pkg = re.split('[=<>]=', line)[0].strip()

            if pkg not in ignore:
                if extras:
                    pkg = 'pkg [%s]' % extras[0]
                packages.add(pkg)

        return packages


if __name__ == '__main__':
    import sys
    print("\n".join(sorted(parse_requirements(
        sys.argv[1] if sys.argv[1:] else 'requirements.txt'))))

requirements.txt

--find-links http://foo.com/pypi
# development
-r requirements-dev.txt

# production
foo
bar==1.0
broken<=1.9
newandshiny >= 3.0
bigpackage [frob]
bloated==10.1 [gargle,fizzle]
-e git+http://git.projects.org/MyProject/#egg=AProject
-e git+http://git.projects.org/OtherProject/#egg=OtherProject==2.7