| """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: |
| firstjulian -- Calculates the Julian date up to the first of the specified |
| year |
| gregorian -- Calculates the Gregorian date based on the Julian day and |
| year |
| julianday -- Calculates the Julian day since the first of the year based |
| on the Gregorian date |
| dayofweek -- Calculates the day of the week from the Gregorian date. |
| strptime -- Calculates the time struct represented by the passed-in string |
| |
| Requires Python 2.2.1 or higher. |
| 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 string import whitespace as whitespace_string |
| |
| __version__ = (2,1,6) |
| __author__ = "Brett Cannon" |
| __email__ = "drifty@bigfoot.com" |
| |
| __all__ = ['strptime'] |
| |
| RegexpType = type(re_compile('')) |
| |
| |
| 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')): |
| try: |
| # Done this way to deal with possible lack of locale info |
| # manifesting itself as the empty string (i.e., Swedish's |
| # lack of AM/PM info). |
| current_format = current_format.replace(old, new) |
| except ValueError: |
| pass |
| 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 such |
| # as with UTC. |
| self.__timezone = self.__pad(time.tzname, 0) |
| |
| def __calc_lang(self): |
| # Set self.lang by using locale.getlocale() or |
| # locale.getdefaultlocale(). |
| current_lang = locale.getlocale(locale.LC_TIME)[0] |
| if current_lang: |
| self.__lang = current_lang |
| else: |
| self.__lang = locale.getdefaultlocale()[0] |
| |
| |
| 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.""" |
| super(TimeRE,self).__init__({ |
| # The " \d" option is to make %c from ANSI C work |
| 'd': r"(?P<d>3[0-1]|[0-2]\d|\d| \d)", |
| 'H': r"(?P<H>2[0-3]|[0-1]\d|\d)", |
| 'I': r"(?P<I>0\d|1[0-2]|\d)", |
| 'j': r"(?P<j>(?:3[0-5]\d|6[0-6])|[0-2]\d\d|\d)", |
| 'm': r"(?P<m>0\d|1[0-2]|\d)", |
| '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': r"(?P<W>5[0-3]|[0-4]\d|\d)", # Same as U |
| 'y': r"(?P<y>\d\d)", |
| 'Y': r"(?P<Y>\d\d\d\d)"}) |
| 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 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. |
| 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.""" |
| processed_format = '' |
| for whitespace in whitespace_string: |
| format = format.replace(whitespace, r'\s*') |
| 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.""" |
| format = "(?#%s)%s" % (self.locale_time.lang,format) |
| return re_compile(self.pattern(format), IGNORECASE) |
| |
| |
| 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. |
| |
| The format argument may either be a regular expression object compiled by |
| strptime(), or a format string. If False is passed in for data_string |
| then the re object calculated for format will be returned. The re object |
| must be used with the same locale as was used to compile the re object. |
| """ |
| locale_time = LocaleTime() |
| if isinstance(format, RegexpType): |
| if format.pattern.find(locale_time.lang) == -1: |
| raise TypeError("re object not created with same language as " |
| "LocaleTime instance") |
| else: |
| compiled_re = format |
| else: |
| compiled_re = TimeRE(locale_time).compile(format) |
| if data_string is False: |
| return compiled_re |
| else: |
| found = compiled_re.match(data_string) |
| if not found: |
| raise ValueError("time data did not match format") |
| year = month = day = hour = minute = second = weekday = julian = tz =-1 |
| found_dict = found.groupdict() |
| for group_key in found_dict.iterkeys(): |
| if group_key == 'y': |
| year = int("%s%s" % |
| (time.strftime("%Y")[:-2], found_dict['y'])) |
| 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': |
| found_zone = found_dict['Z'].lower() |
| if locale_time.timezone[0].lower() == found_zone: |
| tz = 0 |
| elif locale_time.timezone[1].lower() == found_zone: |
| tz = 1 |
| elif locale_time.timezone[2].lower() == found_zone: |
| tz = 0 |
| #XXX <bc>: If calculating fxns are never exposed to the general |
| # populous then just inline calculations. |
| if julian == -1 and year != -1 and month != -1 and day != -1: |
| julian = julianday(year, month, day) |
| if (month == -1 or day == -1) and julian != -1 and year != -1: |
| year, month, day = gregorian(julian, year) |
| if weekday == -1 and year != -1 and month != -1 and day != -1: |
| weekday = dayofweek(year, month, day) |
| 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") |
| |
| def firstjulian(year): |
| """Calculate the Julian date up until the first of the year.""" |
| return ((146097 * (year + 4799)) // 400) - 31738 |
| |
| def julianday(year, month, day): |
| """Calculate the Julian day since the beginning of the year. |
| Calculated from the Gregorian date. |
| """ |
| a = (14 - month) // 12 |
| return (day - 32045 |
| + (((153 * (month + (12 * a) - 3)) + 2) // 5) |
| + ((146097 * (year + 4800 - a)) // 400)) - firstjulian(year) + 1 |
| |
| def gregorian(julian, year): |
| """Return 3-item list containing Gregorian date based on the Julian day.""" |
| a = 32043 + julian + firstjulian(year) |
| b = ((4 * a) + 3) // 146097 |
| c = a - ((146097 * b) // 4) |
| d = ((4 * c) + 3) // 1461 |
| e = c - ((1461 * d) // 4) |
| m = ((5 * e) + 2) // 153 |
| day = 1 + e - (((153 * m) + 2) // 5) |
| month = m + 3 - (12 * (m // 10)) |
| year = (100 * b) + d - 4800 + (m // 10) |
| return [year, month, day] |
| |
| def dayofweek(year, month, day): |
| """Calculate the day of the week (Monday is 0).""" |
| a = (14 - month) // 12 |
| y = year - a |
| weekday = (day + y + ((97 * y) // 400) |
| + ((31 * (month + (12 * a) -2 )) // 12)) % 7 |
| if weekday == 0: |
| return 6 |
| else: |
| return weekday-1 |