timefmt.py 文件源码

def tz_from_string(_option, _opt_str, value, parser):
    """Stores a tzinfo object from a string"""
    if value is not None:
        if value[0] in ['+', '-']:
            # Handed a numeric offset, create an OffsetTzInfo
            valarray = [value[i:i + 2] for i in range(1, len(value), 2)]
            multipliers = [3600, 60]
            offset = 0
            for i in range(min(len(valarray), len(multipliers))):
                offset += int(valarray[i]) * multipliers[i]
            if value[0] == '-':
                offset = -offset
            timezone = OffsetTzInfo(offset = offset)
        else:
            # Value is a lookup, choose pytz over time.tzset
            if tz_pytz:
                try:
                    timezone = pytz.timezone(value)
                except pytz.UnknownTimeZoneError:
                    debug.error("Unknown display timezone specified")
            else:
                if not hasattr(time, 'tzset'):
                    debug.error("This operating system doesn't support tzset, please either specify an offset (eg. +1000) or install pytz")
                timezone = value
        parser.values.tz = timezone