| """Strptime-related classes and functions. |
| |
| CLASSES: |
| LocaleTime -- Discovers and stores locale-specific time information |
| TimeRE -- Creates regexes for pattern matching a string of text containing |
| time information |
| |
| FUNCTIONS: |
| _getlang -- Figure out what language is being used for the locale |
| strptime -- Calculates the time struct represented by the passed-in string |
| |
| """ |
| import time |
| import locale |
| import calendar |
| from re import compile as re_compile |
| from re import IGNORECASE |
| from re import escape as re_escape |
| from datetime import date as datetime_date |
| try: |
| from thread import allocate_lock as _thread_allocate_lock |
| except: |
| from dummy_thread import allocate_lock as _thread_allocate_lock |
| |
| __all__ = [] |
| |
| def _getlang(): |
| # Figure out what the current language is set to. |
| return locale.getlocale(locale.LC_TIME) |
| |
| class LocaleTime(object): |
| """Stores and handles locale-specific information related to time. |
| |
| ATTRIBUTES: |
| f_weekday -- full weekday names (7-item list) |
| a_weekday -- abbreviated weekday names (7-item list) |
| f_month -- full month names (13-item list; dummy value in [0], which |
| is added by code) |
| a_month -- abbreviated month names (13-item list, dummy value in |
| [0], which is added by code) |
| am_pm -- AM/PM representation (2-item list) |
| LC_date_time -- format string for date/time representation (string) |
| LC_date -- format string for date representation (string) |
| LC_time -- format string for time representation (string) |
| timezone -- daylight- and non-daylight-savings timezone representation |
| (2-item list of sets) |
| lang -- Language used by instance (2-item tuple) |
| """ |
| |
| def __init__(self): |
| """Set all attributes. |
| |
| Order of methods called matters for dependency reasons. |
| |
| The locale language is set at the offset and then checked again before |
| exiting. This is to make sure that the attributes were not set with a |
| mix of information from more than one locale. This would most likely |
| happen when using threads where one thread calls a locale-dependent |
| function while another thread changes the locale while the function in |
| the other thread is still running. Proper coding would call for |
| locks to prevent changing the locale while locale-dependent code is |
| running. The check here is done in case someone does not think about |
| doing this. |
| |
| Only other possible issue is if someone changed the timezone and did |
| not call tz.tzset . That is an issue for the programmer, though, |
| since changing the timezone is worthless without that call. |
| |
| """ |
| self.lang = _getlang() |
| self.__calc_weekday() |
| self.__calc_month() |
| self.__calc_am_pm() |
| self.__calc_timezone() |
| self.__calc_date_time() |
| if _getlang() != self.lang: |
| raise ValueError("locale changed during initialization") |
| |
| def __pad(self, seq, front): |
| # Add '' to seq to either the front (is True), else the back. |
| seq = list(seq) |
| if front: |
| seq.insert(0, '') |
| else: |
| seq.append('') |
| return seq |
| |
| def __calc_weekday(self): |
| # Set self.a_weekday and self.f_weekday using the calendar |
| # module. |
| a_weekday = [calendar.day_abbr[i].lower() for i in range(7)] |
| f_weekday = [calendar.day_name[i].lower() for i in range(7)] |
| self.a_weekday = a_weekday |
| self.f_weekday = f_weekday |
| |
| def __calc_month(self): |
| # Set self.f_month and self.a_month using the calendar module. |
| a_month = [calendar.month_abbr[i].lower() for i in range(13)] |
| f_month = [calendar.month_name[i].lower() for i in range(13)] |
| self.a_month = a_month |
| self.f_month = f_month |
| |
| def __calc_am_pm(self): |
| # Set self.am_pm by using time.strftime(). |
| |
| # The magic date (1999,3,17,hour,44,55,2,76,0) is not really that |
| # magical; just happened to have used it everywhere else where a |
| # static date was needed. |
| am_pm = [] |
| for hour in (01,22): |
| time_tuple = time.struct_time((1999,3,17,hour,44,55,2,76,0)) |
| am_pm.append(time.strftime("%p", time_tuple).lower()) |
| self.am_pm = am_pm |
| |
| def __calc_date_time(self): |
| # Set self.date_time, self.date, & self.time by using |
| # time.strftime(). |
| |
| # Use (1999,3,17,22,44,55,2,76,0) for magic date because the amount of |
| # overloaded numbers is minimized. The order in which searches for |
| # values within the format string is very important; it eliminates |
| # possible ambiguity for what something represents. |
| time_tuple = time.struct_time((1999,3,17,22,44,55,2,76,0)) |
| date_time = [None, None, None] |
| date_time[0] = time.strftime("%c", time_tuple).lower() |
| date_time[1] = time.strftime("%x", time_tuple).lower() |
| date_time[2] = time.strftime("%X", time_tuple).lower() |
| replacement_pairs = [('%', '%%'), (self.f_weekday[2], '%A'), |
| (self.f_month[3], '%B'), (self.a_weekday[2], '%a'), |
| (self.a_month[3], '%b'), (self.am_pm[1], '%p'), |
| ('1999', '%Y'), ('99', '%y'), ('22', '%H'), |
| ('44', '%M'), ('55', '%S'), ('76', '%j'), |
| ('17', '%d'), ('03', '%m'), ('3', '%m'), |
| # '3' needed for when no leading zero. |
| ('2', '%w'), ('10', '%I')] |
| replacement_pairs.extend([(tz, "%Z") for tz_values in self.timezone |
| for tz in tz_values]) |
| for offset,directive in ((0,'%c'), (1,'%x'), (2,'%X')): |
| current_format = date_time[offset] |
| for old, new in replacement_pairs: |
| # Must deal with possible lack of locale info |
| # manifesting itself as the empty string (e.g., Swedish's |
| # lack of AM/PM info) or a platform returning a tuple of empty |
| # strings (e.g., MacOS 9 having timezone as ('','')). |
| if old: |
| current_format = current_format.replace(old, new) |
| # If %W is used, then Sunday, 2005-01-03 will fall on week 0 since |
| # 2005-01-03 occurs before the first Monday of the year. Otherwise |
| # %U is used. |
| time_tuple = time.struct_time((1999,1,3,1,1,1,6,3,0)) |
| if '00' in time.strftime(directive, time_tuple): |
| U_W = '%W' |
| else: |
| U_W = '%U' |
| date_time[offset] = current_format.replace('11', U_W) |
| self.LC_date_time = date_time[0] |
| self.LC_date = date_time[1] |
| self.LC_time = date_time[2] |
| |
| def __calc_timezone(self): |
| # Set self.timezone by using time.tzname. |
| # Do not worry about possibility of time.tzname[0] == timetzname[1] |
| # and time.daylight; handle that in strptime . |
| try: |
| time.tzset() |
| except AttributeError: |
| pass |
| no_saving = frozenset(["utc", "gmt", time.tzname[0].lower()]) |
| if time.daylight: |
| has_saving = frozenset([time.tzname[1].lower()]) |
| else: |
| has_saving = frozenset() |
| self.timezone = (no_saving, has_saving) |
| |
| |
| class TimeRE(dict): |
| """Handle conversion from format directives to regexes.""" |
| |
| def __init__(self, locale_time=None): |
| """Create keys/values. |
| |
| Order of execution is important for dependency reasons. |
| |
| """ |
| if locale_time: |
| self.locale_time = locale_time |
| else: |
| self.locale_time = LocaleTime() |
| base = super(TimeRE, self) |
| base.__init__({ |
| # The " \d" part of the regex is to make %c from ANSI C work |
| 'd': r"(?P<d>3[0-1]|[1-2]\d|0[1-9]|[1-9]| [1-9])", |
| 'f': r"(?P<f>[0-9]{1,6})", |
| 'H': r"(?P<H>2[0-3]|[0-1]\d|\d)", |
| 'I': r"(?P<I>1[0-2]|0[1-9]|[1-9])", |
| 'j': r"(?P<j>36[0-6]|3[0-5]\d|[1-2]\d\d|0[1-9]\d|00[1-9]|[1-9]\d|0[1-9]|[1-9])", |
| 'm': r"(?P<m>1[0-2]|0[1-9]|[1-9])", |
| 'M': r"(?P<M>[0-5]\d|\d)", |
| 'S': r"(?P<S>6[0-1]|[0-5]\d|\d)", |
| 'U': r"(?P<U>5[0-3]|[0-4]\d|\d)", |
| 'w': r"(?P<w>[0-6])", |
| # W is set below by using 'U' |
| 'y': r"(?P<y>\d\d)", |
| #XXX: Does 'Y' need to worry about having less or more than |
| # 4 digits? |
| 'Y': r"(?P<Y>\d\d\d\d)", |
| 'A': self.__seqToRE(self.locale_time.f_weekday, 'A'), |
| 'a': self.__seqToRE(self.locale_time.a_weekday, 'a'), |
| 'B': self.__seqToRE(self.locale_time.f_month[1:], 'B'), |
| 'b': self.__seqToRE(self.locale_time.a_month[1:], 'b'), |
| 'p': self.__seqToRE(self.locale_time.am_pm, 'p'), |
| 'Z': self.__seqToRE((tz for tz_names in self.locale_time.timezone |
| for tz in tz_names), |
| 'Z'), |
| '%': '%'}) |
| base.__setitem__('W', base.__getitem__('U').replace('U', 'W')) |
| base.__setitem__('c', self.pattern(self.locale_time.LC_date_time)) |
| base.__setitem__('x', self.pattern(self.locale_time.LC_date)) |
| base.__setitem__('X', self.pattern(self.locale_time.LC_time)) |
| |
| def __seqToRE(self, to_convert, directive): |
| """Convert a list to a regex string for matching a directive. |
| |
| Want possible matching values to be from longest to shortest. This |
| prevents the possibility of a match occuring for a value that also |
| a substring of a larger value that should have matched (e.g., 'abc' |
| matching when 'abcdef' should have been the match). |
| |
| """ |
| to_convert = sorted(to_convert, key=len, reverse=True) |
| for value in to_convert: |
| if value != '': |
| break |
| else: |
| return '' |
| regex = '|'.join(re_escape(stuff) for stuff in to_convert) |
| regex = '(?P<%s>%s' % (directive, regex) |
| return '%s)' % regex |
| |
| def pattern(self, format): |
| """Return regex pattern for the format string. |
| |
| Need to make sure that any characters that might be interpreted as |
| regex syntax are escaped. |
| |
| """ |
| processed_format = '' |
| # The sub() call escapes all characters that might be misconstrued |
| # as regex syntax. Cannot use re.escape since we have to deal with |
| # format directives (%m, etc.). |
| regex_chars = re_compile(r"([\\.^$*+?\(\){}\[\]|])") |
| format = regex_chars.sub(r"\\\1", format) |
| whitespace_replacement = re_compile('\s+') |
| format = whitespace_replacement.sub('\s+', format) |
| while '%' in format: |
| directive_index = format.index('%')+1 |
| processed_format = "%s%s%s" % (processed_format, |
| format[:directive_index-1], |
| self[format[directive_index]]) |
| format = format[directive_index+1:] |
| return "%s%s" % (processed_format, format) |
| |
| def compile(self, format): |
| """Return a compiled re object for the format string.""" |
| return re_compile(self.pattern(format), IGNORECASE) |
| |
| _cache_lock = _thread_allocate_lock() |
| # DO NOT modify _TimeRE_cache or _regex_cache without acquiring the cache lock |
| # first! |
| _TimeRE_cache = TimeRE() |
| _CACHE_MAX_SIZE = 5 # Max number of regexes stored in _regex_cache |
| _regex_cache = {} |
| |
| def _calc_julian_from_U_or_W(year, week_of_year, day_of_week, week_starts_Mon): |
| """Calculate the Julian day based on the year, week of the year, and day of |
| the week, with week_start_day representing whether the week of the year |
| assumes the week starts on Sunday or Monday (6 or 0).""" |
| first_weekday = datetime_date(year, 1, 1).weekday() |
| # If we are dealing with the %U directive (week starts on Sunday), it's |
| # easier to just shift the view to Sunday being the first day of the |
| # week. |
| if not week_starts_Mon: |
| first_weekday = (first_weekday + 1) % 7 |
| day_of_week = (day_of_week + 1) % 7 |
| # Need to watch out for a week 0 (when the first day of the year is not |
| # the same as that specified by %U or %W). |
| week_0_length = (7 - first_weekday) % 7 |
| if week_of_year == 0: |
| return 1 + day_of_week - first_weekday |
| else: |
| days_to_week = week_0_length + (7 * (week_of_year - 1)) |
| return 1 + days_to_week + day_of_week |
| |
| |
| 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 KeyError, 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 = None |
| 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 |
| leap_year_fix = False |
| if year is None and month == 2 and day == 29: |
| year = 1904 # 1904 is first leap year of 20th century |
| leap_year_fix = True |
| elif year is None: |
| year = 1900 |
| # 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() |
| if leap_year_fix: |
| # the caller didn't supply a year but asked for Feb 29th. We couldn't |
| # use the default of 1900 for computations. We set it back to ensure |
| # that February 29th is smaller than March 1st. |
| year = 1900 |
| |
| return (time.struct_time((year, month, day, |
| hour, minute, second, |
| weekday, julian, tz)), fraction) |
| |
| def _strptime_time(data_string, format="%a %b %d %H:%M:%S %Y"): |
| return _strptime(data_string, format)[0] |