I'm looking for a simple Python script that can minify CSS as part of a web-site deployment process. (Python is the only scripting language supported on the server and full-blown parsers like CSS Utils are overkill for this project).
Basically I'd like jsmin.py for CSS. A single script with no dependencies.
Any ideas?
This seemed like a good task for me to get into python, which has been pending for a while. I hereby present my first ever python script:
import sys, re
with open( sys.argv[1] , 'r' ) as f:
css = f.read()
# remove comments - this will break a lot of hacks :-P
css = re.sub( r'\s*/\*\s*\*/', "$$HACK1$$", css ) # preserve IE<6 comment hack
css = re.sub( r'/\*[\s\S]*?\*/', "", css )
css = css.replace( "$$HACK1$$", '/**/' ) # preserve IE<6 comment hack
# url() doesn't need quotes
css = re.sub( r'url\((["\'])([^)]*)\1\)', r'url(\2)', css )
# spaces may be safely collapsed as generated content will collapse them anyway
css = re.sub( r'\s+', ' ', css )
# shorten collapsable colors: #aabbcc to #abc
css = re.sub( r'#([0-9a-f])\1([0-9a-f])\2([0-9a-f])\3(\s|;)', r'#\1\2\3\4', css )
# fragment values can loose zeros
css = re.sub( r':\s*0(\.\d+([cm]m|e[mx]|in|p[ctx]))\s*;', r':\1;', css )
for rule in re.findall( r'([^{]+){([^}]*)}', css ):
# we don't need spaces around operators
selectors = [re.sub( r'(?<=[\[\(>+=])\s+|\s+(?=[=~^$*|>+\]\)])', r'', selector.strip() ) for selector in rule[0].split( ',' )]
# order is important, but we still want to discard repetitions
properties = {}
porder = []
for prop in re.findall( '(.*?):(.*?)(;|$)', rule[1] ):
key = prop[0].strip().lower()
if key not in porder: porder.append( key )
properties[ key ] = prop[1].strip()
# output rule if it contains any declarations
if properties:
print "%s{%s}" % ( ','.join( selectors ), ''.join(['%s:%s;' % (key, properties[key]) for key in porder])[:-1] )
I believe this to work, and output it tests fine on recent Safari, Opera, and Firefox. It will break CSS hacks other than the underscore & /**/ hacks! Do not use a minifier if you have a lot of hacks going on (or put them in a separate file).
Any tips on my python appreciated. Please be gentle though, it's my first time. :-)