utils.py 文件源码

def format_http_datetime(stamp):
    """ Formats datetime to a string following rfc1123 pattern.

        >>> now = datetime(2011, 9, 19, 10, 45, 30, 0, UTC)
        >>> format_http_datetime(now)
        'Mon, 19 Sep 2011 10:45:30 GMT'

        if timezone is not set in datetime instance the ``stamp``
        is assumed to be in UTC (``datetime.utcnow``).

        >>> now = datetime(2011, 9, 19, 10, 45, 30, 0)
        >>> format_http_datetime(now)
        'Mon, 19 Sep 2011 10:45:30 GMT'

        >>> now = datetime.utcnow()
        >>> assert format_http_datetime(now)

        if ``stamp`` is a string just return it

        >>> format_http_datetime('x')
        'x'

        >>> format_http_datetime(100) # doctest: +ELLIPSIS
        Traceback (most recent call last):
            ...
        TypeError: ...
    """
    if isinstance(stamp, datetime):
        if stamp.tzinfo:
            stamp = stamp.astimezone(UTC).timetuple()
        else:
            stamp = localtime(mktime(stamp.timetuple()))
    elif isinstance(stamp, str):
        return stamp
    else:
        raise TypeError('Expecting type ``datetime.datetime``.')

    year, month, day, hh, mm, ss, wd, y, z = stamp
    return "%s, %02d %3s %4d %02d:%02d:%02d GMT" % (
        WEEKDAYS[wd], day, MONTHS[month], year, hh, mm, ss
    )