Monkey patches needed to fix a bug in how Unicode percent-encoded strings are handled in Python's unquote function.

url_monkey.py

import urlparse
import urllib
import urllib2


def patch_unquote():
    urllib.unquote = unquote
    urllib2.unquote = unquote
    urlparse.unquote = unquote

def unquote_to_bytearray(s):
    parts = s.split("%")
    if len(parts) == 1:
        return s  # no unquoting needed

    result = bytearray(parts[0])

    # Process pair-wise hex characters and add them to the byte array
    for item in parts[1:]:
        try:
            result.append(int(item[:2], 16))  # hex part
            for x in item[2:]:
                result.append(x)  # non-hex part
        except ValueError:
            # Invalid hex digit, copy over invalid value verbatim
            result.append("%")
            for x in item:
                result.append(x)

    return result


def unquote(s, encoding="utf-8", errors="replace"):
    """Unquote a percent-encoded string."""
    if isinstance(s, unicode):
        s = s.encode(encoding, errors)
        barray = unquote_to_bytearray(s)
        return barray.decode(encoding, errors)

    barray = unquote_to_bytearray(s)
    return str(barray)