Script for formatting CSS

cssformat.py

#!/usr/bin/env python

#
# Convert CSS/SASS/SCSS/LESS code to Expanded, Compact or Compressed format.
#   written by Mutian Wang <[email protected]>
#
# usage:
#   format_code(code, action)
#

"""Convert CSS/SASS/SCSS/LESS code to Expanded, Compact or Compressed format."""

import re
import sys

def format_code(code, action='compact'):
  actFuns = {
    'expand'    : expand_rules,
    'expand-bs'   : expand_rules,     # expand (break selectors)
    'compact'   : compact_rules,
    'compact-bs'  : compact_rules,    # compact (break selectors)
    'compact-ns'  : compact_ns_rules,   # compact (no spaces)
    'compact-bs-ns' : compact_ns_rules,   # compact (break selectors, no spaces)
    'compress'    : compress_rules
  }

  # Protect Urls
  urls = re.findall(r'url\([^\)]+\)', code)
  code = re.sub(r'url\([^\)]+\)', 'url(~)', code)

  # Pre Process
  code = re.sub(r'\s*([\{\}:;,])\s*', r'\1', code)  # remove \s before and after characters {}:;,
  code = re.sub(r',[\d\s\.\#\+>:]*\{', '{', code)   # remove invalid selector
  code = re.sub(r';\s*;', ';', code)          # remove superfluous ;

  if action != 'compress':

    # comment
    code = re.sub(r'\/\*\s*([\s\S]+?)\s*\*\/', r'/* \1 */', code) # add space before and after comment content
    code = re.sub(r'\}\s*(\/\*[\s\S]+?\*\/)\s*', r'}\n\1\n', code)  # add \n before and after outside comment

    # selectors group
    if re.search(r'-bs', action):
      code = break_selectors(code)        # break after selectors' ,
    else:
      code = re.sub(r',(\S)', r', \1', code)    # add space after ,

    # add space after :
    if re.search(r'-ns', action):
      code = re.sub(r', +', ',', code)      # remove space after ,
      code = re.sub(r'\s+!important', '!important', code)       # remove space before !important
    else:
      code = re.sub(r'([A-Za-z-]):([^;\{]+[;\}])', r'\1: \2', code) # add space after properties' :
      code = re.sub(r'(http[s]?:) \/\/', r'\1//', code)       # fix space after http[s]:
      code = re.sub(r'\s*!important', ' !important', code)      # add space before !important

  # Process Action Rules
  code = actFuns[action](code)

  # Trim
  code = re.sub(r'^\s*(\S+(\s+\S+)*)\s*$', r'\1', code)

  # Indent
  if action != 'compress':
    code = indent_code(code)
  else:
    code = remove_last_semicolon(code)

  # Backfill Urls
  while re.search(r'url\(~\)', code):
    code = re.sub(r'url\(~\)', urls[0], code, 1)
    del urls[0]

  return code


# Expand Rules
def expand_rules(code):
  code = re.sub(r'(\S)\{(\S)', r'\1 {\n\2', code)             # add space before { , and add \n after {

  code = re.sub(r'(\S);([^\}])', r'\1;\n\2', code)            # add \n after ;
  # code = re.sub(r'(url\([^\)]*data:[\w\/-:]+)\;\s*', r'\1; ', code)   # fix space after ; in data url
  # code = re.sub(r'(url\([^\)]*charset=[\w-]+)\;\s*', r'\1; ', code)   # fix space after ; in data url
  code = re.sub(r'\;\s*(\/\*[^\n]*\*\/)\s*', r'; \1\n', code)       # fix comment after ;
  code = re.sub(r'((?:@charset|@import)[^;]+;)\s*', r'\1\n', code)    # add \n after @charset & @import

  code = re.sub(r'([^\}])\s*\}', r'\1\n}', code)              # add \n before }
  code = re.sub(r'\}', r'}\n', code)                    # add \n after }

  return code


# Compact Rules
def compact_rules(code):
  code = re.sub(r'(\S)\{(\S)', r'\1 { \2', code)              # add space and after {
  code = re.sub(r'((@media|@[\w-]*keyframes)[^\{]+\{)\s*', r'\1\n', code) # add \n after @media {

  code = re.sub(r'(\S);([^\}])', r'\1; \2', code)             # add space after ;
  code = re.sub(r'\;\s*(\/\*[^\n]*\*\/)\s*', r'; \1\n', code)       # fix comment after ;
  code = re.sub(r'((?:@charset|@import)[^;]+;)\s*', r'\1\n', code)    # add \n after @charset & @import
  code = re.sub(r';\s*([^\};]+?\{)', r';\n\1', code)            # add \n before included selector

  code = re.sub(r'(\/\*[^\n]*\*\/)\s+\}', r'\1}', code)         # remove \n between comment and }
  code = re.sub(r'(\S)\}', r'\1 }', code)                 # add space before }
  code = re.sub(r'\}\s*', r'}\n', code)                 # add \n after }

  return code


# Compact Rules (no space)
def compact_ns_rules(code):
  code = re.sub(r'((@media|@[\w-]*keyframes)[^\{]+\{)\s*', r'\1\n', code) # add \n after @media {

  code = re.sub(r'\;\s*(\/\*[^\n]*\*\/)\s*', r'; \1\n', code)       # fix comment after ;
  code = re.sub(r'((?:@charset|@import)[^;]+;)\s*', r'\1\n', code)    # add \n after @charset & @import
  code = re.sub(r';\s*([^\};]+?\{)', r';\n\1', code)            # add \n before included selector

  code = re.sub(r'(\/\*[^\n]*\*\/)\s+\}', r'\1}', code)         # remove \n between comment and }
  code = re.sub(r'\}\s*', r'}\n', code)                 # add \n after }

  return code


# Compress Rules
def compress_rules(code):
  code = re.sub(r'\/\*[\s\S]+?\*\/', '', code)            # remove non-empty comments, /**/ maybe a hack
  code = re.sub(r'\s*([\{\}:;,])\s*', r'\1', code)          # remove \s before and after characters {}:;, again
  code = re.sub(r'\s+!important', '!important', code)         # remove space before !important
  code = re.sub(r'((?:@charset|@import)[^;]+;)\s*', r'\1\n', code)  # add \n after @charset & @import

  return code


# Break after Selector
def break_selectors(code):
  block = code.split('}')

  for i in range(len(block)):
    b = block[i].split('{')
    for j in range(len(b)):
      if b[j].count('@import'):
        s = b[j].split(';')
        for k in range(len(s)):
          if not s[k].count('@import'):         # ignore @import
            s[k] = re.sub(r',(\S)', r',\n\1', s[k])
        b[j] = ';'.join(s)
      else:
        if j == len(b) - 1 or b[j].count('@media'):
          b[j] = re.sub(r',(\S)', r', \1', b[j])      # add space after properties' or @media's ,
        else:
          b[j] = re.sub(r',(\S)', r',\n\1', b[j])     # add \n after selectors' ,
    block[i] = '{'.join(b)

  code = '}'.join(block)

  return code


# Code Indent
def indent_code(code):
  lines = code.split('\n')
  level = 0

  for i in range(len(lines)):
    increment = lines[i].count('{') - lines[i].count('}')
    level = level + increment
    thisLevel = level - increment if increment > 0 else level
    lines[i] = re.sub(r'\s*(\S+(\s+\S+)*)\s*', r'\1', lines[i]) # trim
    lines[i] = '\t' * thisLevel + lines[i]

  code = '\n'.join(lines)

  return code


# Remove Last Semicolon
def remove_last_semicolon(code):
  block = code.split('}')

  for i in range(len(block)):
    block[i] = re.sub(r';$', '', block[i])

  code = '}'.join(block)

  return code

def main():
  data = sys.stdin.read()

  code = format_code(data, 'expand')

  sys.stdout.write(code)

if __name__ == '__main__':
  main()

Just threw this together in a couple of minutes so that I can use this in in Vim. From the Sublime Text plugin by Mutian Wang.

I use it like this:

I put the script in a directory included in my PATH, giving it execute perms (chmod +x cssformat.py). As far as I know, passing the visual selection to an external command is a native Vim thing. No selection should do it to the whole buffer.

The format option is hard-coded—sorry! Obviously this should check sys.argv so you can use all the options.