linter.py

#! /usr/bin/env python

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.


import argparse
from distutils.version import LooseVersion
from operator import itemgetter
import re

import pkg_resources


def cmp_specifier(a, b):
    weight = {'>=': 0, '>': 0,
              '==': 1 , '~=': 1, '!=': 1,
              '<': 2., '<=': 2}
    wa, wb = weight[a[0]], weight[b[0]]
    res = cmp(wa, wb)
    if res != 0:
        return res
    else:
        return cmp(LooseVersion(a[1]), LooseVersion(b[1]))


def lint(requirements):
    output = []
    for line in requirements:
        # comments and empty lines are untouched
        if line.startswith("#") or line == "":
            output.append(line)
            continue

        # split comments
        parts = line.split('#', 1)
        if len(parts) > 1:
            base, comments = parts
        else:
            base, comments = parts[0], ""
            base, comments = base.strip(), comments.strip()
        # split extras specifiers
        parts = base.split(';', 1)
        if len(parts) > 1:
            base, extras = parts
        else:
            base, extras = parts[0], ""
        base, extras = base.strip(), extras.strip()

        req = pkg_resources.Requirement.parse(line)
        name = req.name
        # FIXME: not py3 compliant
        specs = ["%s%s" % x for x in sorted(req.specs, cmp=cmp_specifier)]
        name += ','.join(specs)
        if extras != "":
            name += ";%s" % extras
        if comments != "":
            name += "  #%s" % comments
        output.append(name)
    return output

        
def main():
    parser = argparse.ArgumentParser(description="Normalize requirements files")
    parser.add_argument('requirements',
                        help=['requirements file input'])
    args = parser.parse_args()
    with open(args.requirements) as f:
        requirements = [line.strip() for line in f.readlines()]
    
    for line in lint(requirements):
        print(line)


if __name__ == '__main__':
    main()