def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"):
    """Return a time struct based on the input string and the format string."""
    global _TimeRE_cache, _regex_cache
    with _cache_lock:
        if _getlang() != _TimeRE_cache.locale_time.lang:
            _TimeRE_cache = TimeRE()
            _regex_cache.clear()
        if len(_regex_cache) > _CACHE_MAX_SIZE:
            _regex_cache.clear()
        locale_time = _TimeRE_cache.locale_time
        format_regex = _regex_cache.get(format)
        if not format_regex:
            try:
                format_regex = _TimeRE_cache.compile(format)
            # KeyError raised when a bad format is found; can be specified as
            # \\, in which case it was a stray % but with a space after it
            except __HOLE__, err:
                bad_directive = err.args[0]
                if bad_directive == "\\":
                    bad_directive = "%"
                del err
                raise ValueError("'%s' is a bad directive in format '%s'" %
                                    (bad_directive, format))
            # IndexError only occurs when the format string is "%"
            except IndexError:
                raise ValueError("stray %% in format '%s'" % format)
            _regex_cache[format] = format_regex
    found = format_regex.match(data_string)
    if not found:
        raise ValueError("time data %r does not match format %r" %
                         (data_string, format))
    if len(data_string) != found.end():
        raise ValueError("unconverted data remains: %s" %
                          data_string[found.end():])
    year = 1900
    month = day = 1
    hour = minute = second = fraction = 0
    tz = -1
    # Default to -1 to signify that values not known; not critical to have,
    # though
    week_of_year = -1
    week_of_year_start = -1
    # weekday and julian defaulted to -1 so as to signal need to calculate
    # values
    weekday = julian = -1
    found_dict = found.groupdict()
    for group_key in found_dict.iterkeys():
        # Directives not explicitly handled below:
        #   c, x, X
        #      handled by making out of other directives
        #   U, W
        #      worthless without day of the week
        if group_key == 'y':
            year = int(found_dict['y'])
            # Open Group specification for strptime() states that a %y
            #value in the range of [00, 68] is in the century 2000, while
            #[69,99] is in the century 1900
            if year <= 68:
                year += 2000
            else:
                year += 1900
        elif group_key == 'Y':
            year = int(found_dict['Y'])
        elif group_key == 'm':
            month = int(found_dict['m'])
        elif group_key == 'B':
            month = locale_time.f_month.index(found_dict['B'].lower())
        elif group_key == 'b':
            month = locale_time.a_month.index(found_dict['b'].lower())
        elif group_key == 'd':
            day = int(found_dict['d'])
        elif group_key == 'H':
            hour = int(found_dict['H'])
        elif group_key == 'I':
            hour = int(found_dict['I'])
            ampm = found_dict.get('p', '').lower()
            # If there was no AM/PM indicator, we'll treat this like AM
            if ampm in ('', locale_time.am_pm[0]):
                # We're in AM so the hour is correct unless we're
                # looking at 12 midnight.
                # 12 midnight == 12 AM == hour 0
                if hour == 12:
                    hour = 0
            elif ampm == locale_time.am_pm[1]:
                # We're in PM so we need to add 12 to the hour unless
                # we're looking at 12 noon.
                # 12 noon == 12 PM == hour 12
                if hour != 12:
                    hour += 12
        elif group_key == 'M':
            minute = int(found_dict['M'])
        elif group_key == 'S':
            second = int(found_dict['S'])
        elif group_key == 'f':
            s = found_dict['f']
            # Pad to always return microseconds.
            s += "0" * (6 - len(s))
            fraction = int(s)
        elif group_key == 'A':
            weekday = locale_time.f_weekday.index(found_dict['A'].lower())
        elif group_key == 'a':
            weekday = locale_time.a_weekday.index(found_dict['a'].lower())
        elif group_key == 'w':
            weekday = int(found_dict['w'])
            if weekday == 0:
                weekday = 6
            else:
                weekday -= 1
        elif group_key == 'j':
            julian = int(found_dict['j'])
        elif group_key in ('U', 'W'):
            week_of_year = int(found_dict[group_key])
            if group_key == 'U':
                # U starts week on Sunday.
                week_of_year_start = 6
            else:
                # W starts week on Monday.
                week_of_year_start = 0
        elif group_key == 'Z':
            # Since -1 is default value only need to worry about setting tz if
            # it can be something other than -1.
            found_zone = found_dict['Z'].lower()
            for value, tz_values in enumerate(locale_time.timezone):
                if found_zone in tz_values:
                    # Deal with bad locale setup where timezone names are the
                    # same and yet time.daylight is true; too ambiguous to
                    # be able to tell what timezone has daylight savings
                    if (time.tzname[0] == time.tzname[1] and
                       time.daylight and found_zone not in ("utc", "gmt")):
                        break
                    else:
                        tz = value
                        break
    # If we know the week of the year and what day of that week, we can figure
    # out the Julian day of the year.
    if julian == -1 and week_of_year != -1 and weekday != -1:
        week_starts_Mon = True if week_of_year_start == 0 else False
        julian = _calc_julian_from_U_or_W(year, week_of_year, weekday,
                                            week_starts_Mon)
    # Cannot pre-calculate datetime_date() since can change in Julian
    # calculation and thus could have different value for the day of the week
    # calculation.
    if julian == -1:
        # Need to add 1 to result since first day of the year is 1, not 0.
        julian = datetime_date(year, month, day).toordinal() - \
                  datetime_date(year, 1, 1).toordinal() + 1
    else:  # Assume that if they bothered to include Julian day it will
           # be accurate.
        datetime_result = datetime_date.fromordinal((julian - 1) + datetime_date(year, 1, 1).toordinal())
        year = datetime_result.year
        month = datetime_result.month
        day = datetime_result.day
    if weekday == -1:
        weekday = datetime_date(year, month, day).weekday()
    return (time.struct_time((year, month, day,
                              hour, minute, second,
                              weekday, julian, tz)), fraction)
dataset/ETHPy150Open azoft-dev-team/imagrium/env/Lib/_strptime.py/_strptime