cssmin.py

   1 #!/usr/bin/env python
   2 # encoding: utf-8
   3
   4 import re
   5
   6 # Constants for use in compression level setting.
   7 NONE = 0
   8 SIMPLE = 1
   9 NORMAL = 2
  10 FULL = 3
  11
  12 _REPLACERS = {
  13     NONE: (None),                           # dummy
  14     SIMPLE: ((r'\/\*.{4,}?\*\/', ''),       # comment
  15              (r'\n\s*\n', r"\n"),           # empty new lines
  16              (r'(^\s*\n)|(\s*\n$)', "")),   # new lines at start or end
  17     NORMAL: ((r'/\*.{4,}?\*/', ''),         # comments
  18              (r"\n", ""),                   # delete new lines
  19              ('[\t ]+', " "),               # change spaces and tabs to one space
  20              (r'\s?([;:{},+>])\s?', r"\1"), # delete space where it is not needed, change ;} to }
  21              (r';}', "}"),                  # because semicolon is not needed there
  22              (r'}', r"}\n")),               # add new line after each rule
  23     FULL: ((r'\/\*.*?\*\/', ''),            # comments
  24            (r"\n", ""),                     # delete new lines
  25            (r'[\t ]+', " "),                # change spaces and tabs to one space
  26            (r'\s?([;:{},+>])\s?', r"\1"),   # delete space where it is not needed, change ;} to }
  27            (r';}', "}")),                   # because semicolon is not needed there
  28 }
  29
  30 class CssMin:
  31     def __init__(self, level=NORMAL):
  32         self.level = level
  33
  34     def compress(self, css):
  35         """Tries to minimize the length of CSS code passed as parameter. Returns string."""
  36         css = css.replace("\r\n", "\n") # get rid of Windows line endings, if they exist
  37         for rule in _REPLACERS[self.level]:
  38             css = re.compile(rule[0], re.MULTILINE|re.UNICODE|re.DOTALL).sub(rule[1], css)
  39         return css
  40
  41 def minimalize(css, level=NORMAL):
  42     """Compress css using level method and return new css as a string."""
  43     return CssMin(level).compress(css)
  44
  45 if __name__ == '__main__':
  46     import sys
  47     if len(sys.argv) <> 3:
  48         print "Usage: %s <input-file> <output-file(can be the same)>" % sys.argv[0]
  49         sys.exit(1)
  50
  51     f = open(sys.argv[1])
  52     inputcss = f.read()
  53     f.close()
  54     open(sys.argv[2], 'w').write(minimalize(inputcss))