gistfile1.py

def check_quotes(logical_line):
    """Raise lint error when using ' instead of " """
    # if there is no double quote sign there's nothing to do
    if not logical_line or logical_line.strip().startswith("#"):
        return

    in_string = False
    single_quotas_are_used = False

    i = 0
    while i < len(logical_line):
        char = logical_line[i]

        if in_string:
            if char == "\"":
                in_string = False
            if char == "\\":
                i += 1  # ignore next char

        elif char == "#":
            break

        elif char == "'":
            single_quotas_are_used = True
            break

        i += 1

    if single_quotas_are_used:
        yield (i, "Q000 Remove Single quotes")