Format and check css files

format.css.py

""" CSS-file formatter

Formats CSS-files without merging rules, preserves comments.
"""
import argparse
import cssutils
import os
import logging

SERIALIZER_PREFERENCES = {'indentClosingBrace': False,
        'keepEmptyRules': True,
        'keepAllProperties': True,
        'listItemSpacer': '\n',
        'omitLastSemicolon': False}

parser = argparse.ArgumentParser(description='Formats css files without '
        'rewriting rules, May loose some comments.')

parser.add_argument('--check', default=False, action='store_true',
        help='Check file for errors and warnings')

parser.add_argument('--replace', default=False, action='store_true',
        help='Replace original file (and backups original)')

parser.add_argument('--force', default=False, action='store_true',
        help='Force replace even if the file contains errors or warnings')

parser.add_argument('paths', metavar='FILES', type=str, nargs='+',
        help='File(s) that should be formatted.')

logging.basicConfig()
l = logging.getLogger()
l.setLevel(logging.DEBUG)

args = parser.parse_args()


def check_file(path, **kwargs):
    """ Check file for errors and warnings and prints them
    """
    return cssutils.parseFile(path, **kwargs)


def replace_file(path, **kwargs):
    """ Format a single css file and overwrite the original """
    try:
        parser = cssutils.CSSParser(**kwargs)
        sheet = parser.parseFile(path)
    except IOError, e:
        print 'Failed to parse file "%s": %s' % (path, e)
        return
    except Exception, e:
        print 'Failed to parse file "%s": %s' % (path, e)
        return
    try:
        counter = 0
        while os.path.isfile('%s.bak%d' % (path, counter)):
            counter = counter + 1
        dest = '%s.bak%d' % (path, counter)
        os.rename(path, dest)
    except Exception, e:
        print "Failed to backup file '%s' to '%s': %s" % (path, dest, e)
        return

    for k in SERIALIZER_PREFERENCES:
        sheet.setSerializerPref(k, SERIALIZER_PREFERENCES[k])

    with open(path, 'w') as f:
        f.write(sheet.cssText)

for path in args.paths:
    path = os.path.abspath(path)
    if args.check:
        check_file(path)
    if args.replace:
        replace_file(path, raiseExceptions=not args.force)
    else:
        parser = cssutils.CSSParser()
        sheet = parser.parseFile(path)
        for k in SERIALIZER_PREFERENCES:
            sheet.setSerializerPref(k, SERIALIZER_PREFERENCES[k])
        print sheet.cssText