def _find_cols_in_sig(self, sig):
    for match in re.finditer('(?:"(.+?)")|([a-z0-9_]+)', sig, re.I):
        (yield (match.group(1) or match.group(2)))
def _find_cols_in_sig(self, sig):
    for match in re.finditer('(?:"(.+?)")|([a-z0-9_]+)', sig, re.I):
        (yield (match.group(1) or match.group(2)))