gistfile1.py

# Replace all of the lxml cssselect calls in a python script with
# equivalent xpath calls.
import re
import sys
import lxml.cssselect


def cssselect_replace(match):
    xpath = lxml.cssselect.css_to_xpath(match.group(2))
    xpath = xpath.replace("'", "\\'").replace('"', '\\"')
    return ".xpath(%s%s%s)" % (match.group(1), xpath, match.group(1))


if __name__ == '__main__':
    try:
        filename = sys.argv[1]
    except IndexError:
        print "enter a file to convert"
        sys.exit(1)

    with open(filename) as f:
        text = f.read()

    text = re.sub(r"\.cssselect\((['\"])([^\)]*)\1\)",
                  cssselect_replace, text)

    with open(filename.replace('.py', '.py.better'), 'w') as w:
        w.write(text)