| """Strptime-related classes and functions. |
| |
| CLASSES: |
| LocaleTime -- Discovers and/or stores locale-specific time information |
| TimeRE -- Creates regexes for pattern matching a string of text containing |
| time information as is returned by time.strftime() |
| |
| FUNCTIONS: |
| _getlang -- Figure out what language is being used for the locale |
| strptime -- Calculates the time struct represented by the passed-in string |
| |
| Requires Python 2.2.1 or higher (mainly because of the use of property()). |
| Can be used in Python 2.2 if the following line is added: |
| True = 1; False = 0 |
| """ |
| import time |
| import locale |
| import calendar |
| from re import compile as re_compile |
| from re import IGNORECASE |
| from datetime import date as datetime_date |
| |
| __author__ = "Brett Cannon" |
| __email__ = "brett@python.org" |
| |
| __all__ = ['strptime'] |
| |
| def _getlang(): |
| # Figure out what the current language is set to. |
| current_lang = locale.getlocale(locale.LC_TIME)[0] |
| if current_lang: |
| return current_lang |
| else: |
| current_lang = locale.getdefaultlocale()[0] |
| if current_lang: |
| return current_lang |
| else: |
| return '' |
| |
| class LocaleTime(object): |
| """Stores and handles locale-specific information related to time. |
| |
| ATTRIBUTES (all read-only after instance creation! Instance variables that |
| store the values have mangled names): |
| f_weekday -- full weekday names (7-item list) |
| a_weekday -- abbreviated weekday names (7-item list) |
| f_month -- full weekday names (14-item list; dummy value in [0], which |
| is added by code) |
| a_month -- abbreviated weekday 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 |
| (3-item list; code tacks on blank item at end for |
| possible lack of timezone such as UTC) |
| lang -- Language used by instance (string) |
| """ |
| |
| def __init__(self, f_weekday=None, a_weekday=None, f_month=None, |
| a_month=None, am_pm=None, LC_date_time=None, LC_time=None, |
| LC_date=None, timezone=None, lang=None): |
| """Optionally set attributes with passed-in values.""" |
| if f_weekday is None: |
| self.__f_weekday = None |
| elif len(f_weekday) == 7: |
| self.__f_weekday = list(f_weekday) |
| else: |
| raise TypeError("full weekday names must be a 7-item sequence") |
| if a_weekday is None: |
| self.__a_weekday = None |
| elif len(a_weekday) == 7: |
| self.__a_weekday = list(a_weekday) |
| else: |
| raise TypeError( |
| "abbreviated weekday names must be a 7-item sequence") |
| if f_month is None: |
| self.__f_month = None |
| elif len(f_month) == 12: |
| self.__f_month = self.__pad(f_month, True) |
| else: |
| raise TypeError("full month names must be a 12-item sequence") |
| if a_month is None: |
| self.__a_month = None |
| elif len(a_month) == 12: |
| self.__a_month = self.__pad(a_month, True) |
| else: |
| raise TypeError( |
| "abbreviated month names must be a 12-item sequence") |
| if am_pm is None: |
| self.__am_pm = None |
| elif len(am_pm) == 2: |
| self.__am_pm = am_pm |
| else: |
| raise TypeError("AM/PM representation must be a 2-item sequence") |
| self.__LC_date_time = LC_date_time |
| self.__LC_time = LC_time |
| self.__LC_date = LC_date |
| self.__timezone = timezone |
| if timezone: |
| if len(timezone) != 2: |
| raise TypeError("timezone names must contain 2 items") |
| else: |
| self.__timezone = self.__pad(timezone, False) |
| self.__lang = lang |
| |
| def __pad(self, seq, front): |
| # Add '' to seq to either front (is True), else the back. |
| seq = list(seq) |
| if front: |
| seq.insert(0, '') |
| else: |
| seq.append('') |
| return seq |
| |
| def __set_nothing(self, stuff): |
| # Raise TypeError when trying to set an attribute. |
| raise TypeError("attribute does not support assignment") |
| |
| def __get_f_weekday(self): |
| # Fetch self.f_weekday. |
| if not self.__f_weekday: |
| self.__calc_weekday() |
| return self.__f_weekday |
| |
| def __get_a_weekday(self): |
| # Fetch self.a_weekday. |
| if not self.__a_weekday: |
| self.__calc_weekday() |
| return self.__a_weekday |
| |
| f_weekday = property(__get_f_weekday, __set_nothing, |
| doc="Full weekday names") |
| a_weekday = property(__get_a_weekday, __set_nothing, |
| doc="Abbreviated weekday names") |
| |
| def __get_f_month(self): |
| # Fetch self.f_month. |
| if not self.__f_month: |
| self.__calc_month() |
| return self.__f_month |
| |
| def __get_a_month(self): |
| # Fetch self.a_month. |
| if not self.__a_month: |
| self.__calc_month() |
| return self.__a_month |
| |
| f_month = property(__get_f_month, __set_nothing, |
| doc="Full month names (dummy value at index 0)") |
| a_month = property(__get_a_month, __set_nothing, |
| doc="Abbreviated month names (dummy value at index 0)") |
| |
| def __get_am_pm(self): |
| # Fetch self.am_pm. |
| if not self.__am_pm: |
| self.__calc_am_pm() |
| return self.__am_pm |
| |
| am_pm = property(__get_am_pm, __set_nothing, doc="AM/PM representation") |
| |
| def __get_timezone(self): |
| # Fetch self.timezone. |
| if not self.__timezone: |
| self.__calc_timezone() |
| return self.__timezone |
| |
| timezone = property(__get_timezone, __set_nothing, |
| doc="Timezone representation (dummy value at index 2)") |
| |
| def __get_LC_date_time(self): |
| # Fetch self.LC_date_time. |
| if not self.__LC_date_time: |
| self.__calc_date_time() |
| return self.__LC_date_time |
| |
| def __get_LC_date(self): |
| # Fetch self.LC_date. |
| if not self.__LC_date: |
| self.__calc_date_time() |
| return self.__LC_date |
| |
| def __get_LC_time(self): |
| # Fetch self.LC_time. |
| if not self.__LC_time: |
| self.__calc_date_time() |
| return self.__LC_time |
| |
| LC_date_time = property( |
| __get_LC_date_time, __set_nothing, |
| doc= |
| "Format string for locale's date/time representation ('%c' format)") |
| LC_date = property(__get_LC_date, __set_nothing, |
| doc="Format string for locale's date representation ('%x' format)") |
| LC_time = property(__get_LC_time, __set_nothing, |
| doc="Format string for locale's time representation ('%X' format)") |
| |
| def __get_lang(self): |
| # Fetch self.lang. |
| if not self.__lang: |
| self.__calc_lang() |
| return self.__lang |
| |
| lang = property(__get_lang, __set_nothing, |
| doc="Language used for instance") |
| |
| def __calc_weekday(self): |
| # Set self.__a_weekday and self.__f_weekday using the calendar |
| # module. |
| a_weekday = [calendar.day_abbr[i] for i in range(7)] |
| f_weekday = [calendar.day_name[i] for i in range(7)] |
| if not self.__a_weekday: |
| self.__a_weekday = a_weekday |
| if not self.__f_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] for i in range(13)] |
| f_month = [calendar.month_name[i] for i in range(13)] |
| if not self.__a_month: |
| self.__a_month = a_month |
| if not self.__f_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)) |
| 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) |
| date_time[1] = time.strftime("%x", time_tuple) |
| date_time[2] = time.strftime("%X", time_tuple) |
| for offset,directive in ((0,'%c'), (1,'%x'), (2,'%X')): |
| current_format = date_time[offset] |
| for old, new in ( |
| ('%', '%%'), (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'), |
| (self.timezone[0], '%Z'), (self.timezone[1], '%Z'), |
| ('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')): |
| # 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) |
| time_tuple = time.struct_time((1999,1,3,1,1,1,6,3,0)) |
| if time.strftime(directive, time_tuple).find('00'): |
| U_W = '%U' |
| else: |
| U_W = '%W' |
| date_time[offset] = current_format.replace('11', U_W) |
| if not self.__LC_date_time: |
| self.__LC_date_time = date_time[0] |
| if not self.__LC_date: |
| self.__LC_date = date_time[1] |
| if not self.__LC_time: |
| self.__LC_time = date_time[2] |
| |
| def __calc_timezone(self): |
| # Set self.__timezone by using time.tzname. |
| # |
| # Empty string used for matching when timezone is not used/needed. |
| try: |
| time.tzset() |
| except AttributeError: |
| pass |
| time_zones = ["UTC", "GMT"] |
| if time.daylight: |
| time_zones.extend(time.tzname) |
| else: |
| time_zones.append(time.tzname[0]) |
| self.__timezone = self.__pad(time_zones, 0) |
| |
| def __calc_lang(self): |
| # Set self.__lang by using __getlang(). |
| self.__lang = _getlang() |
| |
| |
| |
| class TimeRE(dict): |
| """Handle conversion from format directives to regexes.""" |
| |
| def __init__(self, locale_time=LocaleTime()): |
| """Init inst with non-locale regexes and store LocaleTime object.""" |
| #XXX: Does 'Y' need to worry about having less or more than 4 digits? |
| base = super(TimeRE, self) |
| base.__init__({ |
| # The " \d" option 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])", |
| '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)", |
| 'Y': r"(?P<Y>\d\d\d\d)"}) |
| base.__setitem__('W', base.__getitem__('U')) |
| self.locale_time = locale_time |
| |
| def __getitem__(self, fetch): |
| """Try to fetch regex; if it does not exist, construct it.""" |
| try: |
| return super(TimeRE, self).__getitem__(fetch) |
| except KeyError: |
| constructors = { |
| 'A': lambda: self.__seqToRE(self.locale_time.f_weekday, fetch), |
| 'a': lambda: self.__seqToRE(self.locale_time.a_weekday, fetch), |
| 'B': lambda: self.__seqToRE(self.locale_time.f_month[1:], |
| fetch), |
| 'b': lambda: self.__seqToRE(self.locale_time.a_month[1:], |
| fetch), |
| 'c': lambda: self.pattern(self.locale_time.LC_date_time), |
| 'p': lambda: self.__seqToRE(self.locale_time.am_pm, fetch), |
| 'x': lambda: self.pattern(self.locale_time.LC_date), |
| 'X': lambda: self.pattern(self.locale_time.LC_time), |
| 'Z': lambda: self.__seqToRE(self.locale_time.timezone, fetch), |
| '%': lambda: '%', |
| } |
| if fetch in constructors: |
| self[fetch] = constructors[fetch]() |
| return self[fetch] |
| else: |
| raise |
| |
| def __seqToRE(self, to_convert, directive): |
| """Convert a list to a regex string for matching a directive.""" |
| def sorter(a, b): |
| """Sort based on length. |
| |
| Done in case for some strange reason that names in the locale only |
| differ by a suffix and thus want the name with the suffix to match |
| first. |
| """ |
| try: |
| a_length = len(a) |
| except TypeError: |
| a_length = 0 |
| try: |
| b_length = len(b) |
| except TypeError: |
| b_length = 0 |
| return cmp(b_length, a_length) |
| |
| to_convert = to_convert[:] # Don't want to change value in-place. |
| for value in to_convert: |
| if value != '': |
| break |
| else: |
| return '' |
| to_convert.sort(sorter) |
| regex = '|'.join(to_convert) |
| regex = '(?P<%s>%s' % (directive, regex) |
| return '%s)' % regex |
| |
| def pattern(self, format): |
| """Return re pattern for the format string. |
| |
| Need to make sure that any characters that might be interpreted as |
| regex syntax is escaped. |
| |
| """ |
| processed_format = '' |
| # The sub() call escapes all characters that might be misconstrued |
| # as regex syntax. |
| regex_chars = re_compile(r"([\\.^$*+?{}\[\]|])") |
| format = regex_chars.sub(r"\\\1", format) |
| whitespace_replacement = re_compile('\s+') |
| format = whitespace_replacement.sub('\s*', format) |
| while format.find('%') != -1: |
| 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) |
| |
| # Cached TimeRE; probably only need one instance ever so cache it for performance |
| _locale_cache = TimeRE() |
| # Cached regex objects; same reason as for TimeRE cache |
| _regex_cache = dict() |
| |
| def strptime(data_string, format="%a %b %d %H:%M:%S %Y"): |
| """Return a time struct based on the input data and the format string.""" |
| global _locale_cache |
| global _regex_cache |
| locale_time = _locale_cache.locale_time |
| # If the language changes, caches are invalidated, so clear them |
| if locale_time.lang != _getlang(): |
| _locale_cache = TimeRE() |
| _regex_cache.clear() |
| format_regex = _regex_cache.get(format) |
| if not format_regex: |
| # Limit regex cache size to prevent major bloating of the module; |
| # The value 5 is arbitrary |
| if len(_regex_cache) > 5: |
| _regex_cache.clear() |
| format_regex = _locale_cache.compile(format) |
| _regex_cache[format] = format_regex |
| found = format_regex.match(data_string) |
| if not found: |
| raise ValueError("time data did not match 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 = 0 |
| tz = -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(): |
| 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 = _insensitiveindex(locale_time.f_month, found_dict['B']) |
| elif group_key == 'b': |
| month = _insensitiveindex(locale_time.a_month, found_dict['b']) |
| elif group_key == 'd': |
| day = int(found_dict['d']) |
| elif group_key is '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].lower()): |
| # 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].lower(): |
| # 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 == 'A': |
| weekday = _insensitiveindex(locale_time.f_weekday, |
| found_dict['A']) |
| elif group_key == 'a': |
| weekday = _insensitiveindex(locale_time.a_weekday, |
| found_dict['a']) |
| 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 == '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() |
| if locale_time.timezone[0] == locale_time.timezone[1]: |
| pass #Deals with bad locale setup where timezone info is |
| # the same; first found on FreeBSD 4.4. |
| elif found_zone in ("utc", "gmt"): |
| tz = 0 |
| elif locale_time.timezone[2].lower() == found_zone: |
| tz = 0 |
| elif time.daylight: |
| if locale_time.timezone[3].lower() == found_zone: |
| tz = 1 |
| |
| # 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)) |
| |
| def _insensitiveindex(lst, findme): |
| # Perform a case-insensitive index search. |
| |
| #XXX <bc>: If LocaleTime is not exposed, then consider removing this and |
| # just lowercase when LocaleTime sets its vars and lowercasing |
| # search values. |
| findme = findme.lower() |
| for key,item in enumerate(lst): |
| if item.lower() == findme: |
| return key |
| else: |
| raise ValueError("value not in list") |