A less file compiler.

watchless.py

# -*- coding: utf-8 -*-

"""
Watchless will compile your less files whenever it detects changes.
Accepts one argument, the path where your less files are stored.

Say your less files are store in /static/less and it contains the file
layout.less, watchless will compile it and store the compiled css file
in /static/css/layout.css.

Usage:
    python watchless.py <path to less directory>
"""

import sys
import os
import time


def compile_less(less_file):
    print "Compiling %s" % less_file
    filename, __ = os.path.splitext(os.path.basename(less_file))
    css_file = "%s.css" % os.path.join(CSS_ROOT, filename)
    os.system("lessc %(from)s > %(to)s -x" % {"from": less_file,
                                              "to": css_file})


if __name__ == '__main__':
    if len(sys.argv) != 2:
        print "You need to specify the path where .less files are located."
        sys.exit(1)

    if not os.path.exists(sys.argv[1]):
        print "The path you specified doesn't exist."
        sys.exit(1)

    LESS_ROOT = sys.argv[1]
    CSS_ROOT = os.path.join(os.path.split(LESS_ROOT)[0], 'css')

    # gather all less files
    less_files = {}
    for filename in os.listdir(LESS_ROOT):
        less_file = os.path.join(LESS_ROOT, filename)
        less_files[less_file] = int(os.stat(less_file).st_mtime)

    try:
        while True:
            for less_fle, lastmod in less_files.items():
                newmod = int(os.stat(less_fle).st_mtime)
                if newmod > lastmod:
                    less_files[less_fle] = newmod
                    compile_less(less_fle)
            time.sleep(1)  # zzzzz
    except KeyboardInterrupt:
        sys.exit(0)