| """Concrete date/time and related types -- prototype implemented in Python. |
| |
| See http://www.zope.org/Members/fdrake/DateTimeWiki/FrontPage |
| |
| See also http://dir.yahoo.com/Reference/calendars/ |
| |
| For a primer on DST, including many current DST rules, see |
| http://webexhibits.org/daylightsaving/ |
| |
| For more about DST than you ever wanted to know, see |
| ftp://elsie.nci.nih.gov/pub/ |
| |
| Sources for time zone and DST data: http://www.twinsun.com/tz/tz-link.htm |
| |
| This was originally copied from the sandbox of the CPython CVS repository. |
| Thanks to Tim Peters for suggesting using it. |
| """ |
| |
| import time as _time |
| import math as _math |
| |
| MINYEAR = 1 |
| MAXYEAR = 9999 |
| |
| # Utility functions, adapted from Python's Demo/classes/Dates.py, which |
| # also assumes the current Gregorian calendar indefinitely extended in |
| # both directions. Difference: Dates.py calls January 1 of year 0 day |
| # number 1. The code here calls January 1 of year 1 day number 1. This is |
| # to match the definition of the "proleptic Gregorian" calendar in Dershowitz |
| # and Reingold's "Calendrical Calculations", where it's the base calendar |
| # for all computations. See the book for algorithms for converting between |
| # proleptic Gregorian ordinals and many other calendar systems. |
| |
| _DAYS_IN_MONTH = [None, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31] |
| |
| _DAYS_BEFORE_MONTH = [None] |
| dbm = 0 |
| for dim in _DAYS_IN_MONTH[1:]: |
| _DAYS_BEFORE_MONTH.append(dbm) |
| dbm += dim |
| del dbm, dim |
| |
| def _is_leap(year): |
| "year -> 1 if leap year, else 0." |
| return year % 4 == 0 and (year % 100 != 0 or year % 400 == 0) |
| |
| def _days_in_year(year): |
| "year -> number of days in year (366 if a leap year, else 365)." |
| return 365 + _is_leap(year) |
| |
| def _days_before_year(year): |
| "year -> number of days before January 1st of year." |
| y = year - 1 |
| return y*365 + y//4 - y//100 + y//400 |
| |
| def _days_in_month(year, month): |
| "year, month -> number of days in that month in that year." |
| assert 1 <= month <= 12, month |
| if month == 2 and _is_leap(year): |
| return 29 |
| return _DAYS_IN_MONTH[month] |
| |
| def _days_before_month(year, month): |
| "year, month -> number of days in year preceeding first day of month." |
| if not 1 <= month <= 12: |
| raise ValueError('month must be in 1..12', month) |
| return _DAYS_BEFORE_MONTH[month] + (month > 2 and _is_leap(year)) |
| |
| def _ymd2ord(year, month, day): |
| "year, month, day -> ordinal, considering 01-Jan-0001 as day 1." |
| if not 1 <= month <= 12: |
| raise ValueError('month must be in 1..12', month) |
| dim = _days_in_month(year, month) |
| if not 1 <= day <= dim: |
| raise ValueError('day must be in 1..%d' % dim, day) |
| return (_days_before_year(year) + |
| _days_before_month(year, month) + |
| day) |
| |
| _DI400Y = _days_before_year(401) # number of days in 400 years |
| _DI100Y = _days_before_year(101) # " " " " 100 " |
| _DI4Y = _days_before_year(5) # " " " " 4 " |
| |
| # A 4-year cycle has an extra leap day over what we'd get from pasting |
| # together 4 single years. |
| assert _DI4Y == 4 * 365 + 1 |
| |
| # Similarly, a 400-year cycle has an extra leap day over what we'd get from |
| # pasting together 4 100-year cycles. |
| assert _DI400Y == 4 * _DI100Y + 1 |
| |
| # OTOH, a 100-year cycle has one fewer leap day than we'd get from |
| # pasting together 25 4-year cycles. |
| assert _DI100Y == 25 * _DI4Y - 1 |
| |
| def _ord2ymd(n): |
| "ordinal -> (year, month, day), considering 01-Jan-0001 as day 1." |
| |
| # n is a 1-based index, starting at 1-Jan-1. The pattern of leap years |
| # repeats exactly every 400 years. The basic strategy is to find the |
| # closest 400-year boundary at or before n, then work with the offset |
| # from that boundary to n. Life is much clearer if we subtract 1 from |
| # n first -- then the values of n at 400-year boundaries are exactly |
| # those divisible by _DI400Y: |
| # |
| # D M Y n n-1 |
| # -- --- ---- ---------- ---------------- |
| # 31 Dec -400 -_DI400Y -_DI400Y -1 |
| # 1 Jan -399 -_DI400Y +1 -_DI400Y 400-year boundary |
| # ... |
| # 30 Dec 000 -1 -2 |
| # 31 Dec 000 0 -1 |
| # 1 Jan 001 1 0 400-year boundary |
| # 2 Jan 001 2 1 |
| # 3 Jan 001 3 2 |
| # ... |
| # 31 Dec 400 _DI400Y _DI400Y -1 |
| # 1 Jan 401 _DI400Y +1 _DI400Y 400-year boundary |
| n -= 1 |
| n400, n = divmod(n, _DI400Y) |
| year = n400 * 400 + 1 # ..., -399, 1, 401, ... |
| |
| # Now n is the (non-negative) offset, in days, from January 1 of year, to |
| # the desired date. Now compute how many 100-year cycles precede n. |
| # Note that it's possible for n100 to equal 4! In that case 4 full |
| # 100-year cycles precede the desired day, which implies the desired |
| # day is December 31 at the end of a 400-year cycle. |
| n100, n = divmod(n, _DI100Y) |
| |
| # Now compute how many 4-year cycles precede it. |
| n4, n = divmod(n, _DI4Y) |
| |
| # And now how many single years. Again n1 can be 4, and again meaning |
| # that the desired day is December 31 at the end of the 4-year cycle. |
| n1, n = divmod(n, 365) |
| |
| year += n100 * 100 + n4 * 4 + n1 |
| if n1 == 4 or n100 == 4: |
| assert n == 0 |
| return year-1, 12, 31 |
| |
| # Now the year is correct, and n is the offset from January 1. We find |
| # the month via an estimate that's either exact or one too large. |
| leapyear = n1 == 3 and (n4 != 24 or n100 == 3) |
| assert leapyear == _is_leap(year) |
| month = (n + 50) >> 5 |
| preceding = _DAYS_BEFORE_MONTH[month] + (month > 2 and leapyear) |
| if preceding > n: # estimate is too large |
| month -= 1 |
| preceding -= _DAYS_IN_MONTH[month] + (month == 2 and leapyear) |
| n -= preceding |
| assert 0 <= n < _days_in_month(year, month) |
| |
| # Now the year and month are correct, and n is the offset from the |
| # start of that month: we're done! |
| return year, month, n+1 |
| |
| # Month and day names. For localized versions, see the calendar module. |
| _MONTHNAMES = [None, "Jan", "Feb", "Mar", "Apr", "May", "Jun", |
| "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"] |
| _DAYNAMES = [None, "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"] |
| |
| |
| def _build_struct_time(y, m, d, hh, mm, ss, dstflag): |
| wday = (_ymd2ord(y, m, d) + 6) % 7 |
| dnum = _days_before_month(y, m) + d |
| return _time.struct_time((y, m, d, hh, mm, ss, wday, dnum, dstflag)) |
| |
| def _format_time(hh, mm, ss, us): |
| # Skip trailing microseconds when us==0. |
| result = "%02d:%02d:%02d" % (hh, mm, ss) |
| if us: |
| result += ".%06d" % us |
| return result |
| |
| # Correctly substitute for %z and %Z escapes in strftime formats. |
| def _wrap_strftime(object, format, timetuple): |
| year = timetuple[0] |
| if year < 1900: |
| raise ValueError("year=%d is before 1900; the datetime strftime() " |
| "methods require year >= 1900" % year) |
| # Don't call _utcoffset() or tzname() unless actually needed. |
| zreplace = None # the string to use for %z |
| Zreplace = None # the string to use for %Z |
| |
| # Scan format for %z and %Z escapes, replacing as needed. |
| newformat = [] |
| push = newformat.append |
| i, n = 0, len(format) |
| while i < n: |
| ch = format[i] |
| i += 1 |
| if ch == '%': |
| if i < n: |
| ch = format[i] |
| i += 1 |
| if ch == 'z': |
| if zreplace is None: |
| zreplace = "" |
| if hasattr(object, "_utcoffset"): |
| offset = object._utcoffset() |
| if offset is not None: |
| sign = '+' |
| if offset < 0: |
| offset = -offset |
| sign = '-' |
| h, m = divmod(offset, 60) |
| zreplace = '%c%02d%02d' % (sign, h, m) |
| assert '%' not in zreplace |
| newformat.append(zreplace) |
| elif ch == 'Z': |
| if Zreplace is None: |
| Zreplace = "" |
| if hasattr(object, "tzname"): |
| s = object.tzname() |
| if s is not None: |
| # strftime is going to have at this: escape % |
| Zreplace = s.replace('%', '%%') |
| newformat.append(Zreplace) |
| else: |
| push('%') |
| push(ch) |
| else: |
| push('%') |
| else: |
| push(ch) |
| newformat = "".join(newformat) |
| return _time.strftime(newformat, timetuple) |
| |
| def _call_tzinfo_method(tzinfo, methname, tzinfoarg): |
| if tzinfo is None: |
| return None |
| return getattr(tzinfo, methname)(tzinfoarg) |
| |
| # Just raise TypeError if the arg isn't None or a string. |
| def _check_tzname(name): |
| if name is not None and not isinstance(name, str): |
| raise TypeError("tzinfo.tzname() must return None or string, " |
| "not '%s'" % type(name)) |
| |
| # name is the offset-producing method, "utcoffset" or "dst". |
| # offset is what it returned. |
| # If offset isn't None or timedelta, raises TypeError. |
| # If offset is None, returns None. |
| # Else offset is checked for being in range, and a whole # of minutes. |
| # If it is, its integer value is returned. Else ValueError is raised. |
| def _check_utc_offset(name, offset): |
| assert name in ("utcoffset", "dst") |
| if offset is None: |
| return None |
| if not isinstance(offset, timedelta): |
| raise TypeError("tzinfo.%s() must return None " |
| "or timedelta, not '%s'" % (name, type(offset))) |
| days = offset.days |
| if days < -1 or days > 0: |
| offset = 1440 # trigger out-of-range |
| else: |
| seconds = days * 86400 + offset.seconds |
| minutes, seconds = divmod(seconds, 60) |
| if seconds or offset.microseconds: |
| raise ValueError("tzinfo.%s() must return a whole number " |
| "of minutes" % name) |
| offset = minutes |
| if -1440 < offset < 1440: |
| return offset |
| raise ValueError("%s()=%d, must be in -1439..1439" % (name, offset)) |
| |
| def _check_date_fields(year, month, day): |
| if not MINYEAR <= year <= MAXYEAR: |
| raise ValueError('year must be in %d..%d' % (MINYEAR, MAXYEAR), year) |
| if not 1 <= month <= 12: |
| raise ValueError('month must be in 1..12', month) |
| dim = _days_in_month(year, month) |
| if not 1 <= day <= dim: |
| raise ValueError('day must be in 1..%d' % dim, day) |
| |
| def _check_time_fields(hour, minute, second, microsecond): |
| if not 0 <= hour <= 23: |
| raise ValueError('hour must be in 0..23', hour) |
| if not 0 <= minute <= 59: |
| raise ValueError('minute must be in 0..59', minute) |
| if not 0 <= second <= 59: |
| raise ValueError('second must be in 0..59', second) |
| if not 0 <= microsecond <= 999999: |
| raise ValueError('microsecond must be in 0..999999', microsecond) |
| |
| def _check_tzinfo_arg(tz): |
| if tz is not None and not isinstance(tz, tzinfo): |
| raise TypeError("tzinfo argument must be None or of a tzinfo subclass") |
| |
| |
| # Notes on comparison: In general, datetime module comparison operators raise |
| # TypeError when they don't know how to do a comparison themself. If they |
| # returned NotImplemented instead, comparison could (silently) fall back to |
| # the default compare-objects-by-comparing-their-memory-addresses strategy, |
| # and that's not helpful. There are two exceptions: |
| # |
| # 1. For date and datetime, if the other object has a "timetuple" attr, |
| # NotImplemented is returned. This is a hook to allow other kinds of |
| # datetime-like objects a chance to intercept the comparison. |
| # |
| # 2. Else __eq__ and __ne__ return False and True, respectively. This is |
| # so opertaions like |
| # |
| # x == y |
| # x != y |
| # x in sequence |
| # x not in sequence |
| # dict[x] = y |
| # |
| # don't raise annoying TypeErrors just because a datetime object |
| # is part of a heterogeneous collection. If there's no known way to |
| # compare X to a datetime, saying they're not equal is reasonable. |
| |
| def _cmperror(x, y): |
| raise TypeError("can't compare '%s' to '%s'" % ( |
| type(x).__name__, type(y).__name__)) |
| |
| # This is a start at a struct tm workalike. Goals: |
| # |
| # + Works the same way across platforms. |
| # + Handles all the fields datetime needs handled, without 1970-2038 glitches. |
| # |
| # Note: I suspect it's best if this flavor of tm does *not* try to |
| # second-guess timezones or DST. Instead fold whatever adjustments you want |
| # into the minutes argument (and the constructor will normalize). |
| |
| _ORD1970 = _ymd2ord(1970, 1, 1) # base ordinal for UNIX epoch |
| |
| class tmxxx: |
| |
| ordinal = None |
| |
| def __init__(self, year, month, day, hour=0, minute=0, second=0, |
| microsecond=0): |
| # Normalize all the inputs, and store the normalized values. |
| if not 0 <= microsecond <= 999999: |
| carry, microsecond = divmod(microsecond, 1000000) |
| second += carry |
| if not 0 <= second <= 59: |
| carry, second = divmod(second, 60) |
| minute += carry |
| if not 0 <= minute <= 59: |
| carry, minute = divmod(minute, 60) |
| hour += carry |
| if not 0 <= hour <= 23: |
| carry, hour = divmod(hour, 24) |
| day += carry |
| |
| # That was easy. Now it gets muddy: the proper range for day |
| # can't be determined without knowing the correct month and year, |
| # but if day is, e.g., plus or minus a million, the current month |
| # and year values make no sense (and may also be out of bounds |
| # themselves). |
| # Saying 12 months == 1 year should be non-controversial. |
| if not 1 <= month <= 12: |
| carry, month = divmod(month-1, 12) |
| year += carry |
| month += 1 |
| assert 1 <= month <= 12 |
| |
| # Now only day can be out of bounds (year may also be out of bounds |
| # for a datetime object, but we don't care about that here). |
| # If day is out of bounds, what to do is arguable, but at least the |
| # method here is principled and explainable. |
| dim = _days_in_month(year, month) |
| if not 1 <= day <= dim: |
| # Move day-1 days from the first of the month. First try to |
| # get off cheap if we're only one day out of range (adjustments |
| # for timezone alone can't be worse than that). |
| if day == 0: # move back a day |
| month -= 1 |
| if month > 0: |
| day = _days_in_month(year, month) |
| else: |
| year, month, day = year-1, 12, 31 |
| elif day == dim + 1: # move forward a day |
| month += 1 |
| day = 1 |
| if month > 12: |
| month = 1 |
| year += 1 |
| else: |
| self.ordinal = _ymd2ord(year, month, 1) + (day - 1) |
| year, month, day = _ord2ymd(self.ordinal) |
| |
| self.year, self.month, self.day = year, month, day |
| self.hour, self.minute, self.second = hour, minute, second |
| self.microsecond = microsecond |
| |
| def toordinal(self): |
| """Return proleptic Gregorian ordinal for the year, month and day. |
| |
| January 1 of year 1 is day 1. Only the year, month and day values |
| contribute to the result. |
| """ |
| if self.ordinal is None: |
| self.ordinal = _ymd2ord(self.year, self.month, self.day) |
| return self.ordinal |
| |
| def time(self): |
| "Return Unixish timestamp, as a float (assuming UTC)." |
| days = self.toordinal() - _ORD1970 # convert to UNIX epoch |
| seconds = ((days * 24. + self.hour)*60. + self.minute)*60. |
| return seconds + self.second + self.microsecond / 1e6 |
| |
| def ctime(self): |
| "Return ctime() style string." |
| weekday = self.toordinal() % 7 or 7 |
| return "%s %s %2d %02d:%02d:%02d %04d" % ( |
| _DAYNAMES[weekday], |
| _MONTHNAMES[self.month], |
| self.day, |
| self.hour, self.minute, self.second, |
| self.year) |
| |
| class timedelta(object): |
| """Represent the difference between two datetime objects. |
| |
| Supported operators: |
| |
| - add, subtract timedelta |
| - unary plus, minus, abs |
| - compare to timedelta |
| - multiply, divide by int/long |
| |
| In addition, datetime supports subtraction of two datetime objects |
| returning a timedelta, and addition or subtraction of a datetime |
| and a timedelta giving a datetime. |
| |
| Representation: (days, seconds, microseconds). Why? Because I |
| felt like it. |
| """ |
| |
| def __new__(cls, days=0, seconds=0, microseconds=0, |
| # XXX The following should only be used as keyword args: |
| milliseconds=0, minutes=0, hours=0, weeks=0): |
| # Doing this efficiently and accurately in C is going to be difficult |
| # and error-prone, due to ubiquitous overflow possibilities, and that |
| # C double doesn't have enough bits of precision to represent |
| # microseconds over 10K years faithfully. The code here tries to make |
| # explicit where go-fast assumptions can be relied on, in order to |
| # guide the C implementation; it's way more convoluted than speed- |
| # ignoring auto-overflow-to-long idiomatic Python could be. |
| |
| # XXX Check that all inputs are ints, longs or floats. |
| |
| # Final values, all integer. |
| # s and us fit in 32-bit signed ints; d isn't bounded. |
| d = s = us = 0 |
| |
| # Normalize everything to days, seconds, microseconds. |
| days += weeks*7 |
| seconds += minutes*60 + hours*3600 |
| microseconds += milliseconds*1000 |
| |
| # Get rid of all fractions, and normalize s and us. |
| # Take a deep breath <wink>. |
| if isinstance(days, float): |
| dayfrac, days = _math.modf(days) |
| daysecondsfrac, daysecondswhole = _math.modf(dayfrac * (24.*3600.)) |
| assert daysecondswhole == int(daysecondswhole) # can't overflow |
| s = int(daysecondswhole) |
| assert days == long(days) |
| d = long(days) |
| else: |
| daysecondsfrac = 0.0 |
| d = days |
| assert isinstance(daysecondsfrac, float) |
| assert abs(daysecondsfrac) <= 1.0 |
| assert isinstance(d, (int, long)) |
| assert abs(s) <= 24 * 3600 |
| # days isn't referenced again before redefinition |
| |
| if isinstance(seconds, float): |
| secondsfrac, seconds = _math.modf(seconds) |
| assert seconds == long(seconds) |
| seconds = long(seconds) |
| secondsfrac += daysecondsfrac |
| assert abs(secondsfrac) <= 2.0 |
| else: |
| secondsfrac = daysecondsfrac |
| # daysecondsfrac isn't referenced again |
| assert isinstance(secondsfrac, float) |
| assert abs(secondsfrac) <= 2.0 |
| |
| assert isinstance(seconds, (int, long)) |
| days, seconds = divmod(seconds, 24*3600) |
| d += days |
| s += int(seconds) # can't overflow |
| assert isinstance(s, int) |
| assert abs(s) <= 2 * 24 * 3600 |
| # seconds isn't referenced again before redefinition |
| |
| usdouble = secondsfrac * 1e6 |
| assert abs(usdouble) < 2.1e6 # exact value not critical |
| # secondsfrac isn't referenced again |
| |
| if isinstance(microseconds, float): |
| microseconds += usdouble |
| microseconds = round(microseconds) |
| seconds, microseconds = divmod(microseconds, 1e6) |
| assert microseconds == int(microseconds) |
| assert seconds == long(seconds) |
| days, seconds = divmod(seconds, 24.*3600.) |
| assert days == long(days) |
| assert seconds == int(seconds) |
| d += long(days) |
| s += int(seconds) # can't overflow |
| assert isinstance(s, int) |
| assert abs(s) <= 3 * 24 * 3600 |
| else: |
| seconds, microseconds = divmod(microseconds, 1000000) |
| days, seconds = divmod(seconds, 24*3600) |
| d += days |
| s += int(seconds) # can't overflow |
| assert isinstance(s, int) |
| assert abs(s) <= 3 * 24 * 3600 |
| microseconds = float(microseconds) |
| microseconds += usdouble |
| microseconds = round(microseconds) |
| assert abs(s) <= 3 * 24 * 3600 |
| assert abs(microseconds) < 3.1e6 |
| |
| # Just a little bit of carrying possible for microseconds and seconds. |
| assert isinstance(microseconds, float) |
| assert int(microseconds) == microseconds |
| us = int(microseconds) |
| seconds, us = divmod(us, 1000000) |
| s += seconds # cant't overflow |
| assert isinstance(s, int) |
| days, s = divmod(s, 24*3600) |
| d += days |
| |
| assert isinstance(d, (int, long)) |
| assert isinstance(s, int) and 0 <= s < 24*3600 |
| assert isinstance(us, int) and 0 <= us < 1000000 |
| |
| self = object.__new__(cls) |
| |
| self.__days = d |
| self.__seconds = s |
| self.__microseconds = us |
| if abs(d) > 999999999: |
| raise OverflowError("timedelta # of days is too large: %d" % d) |
| |
| return self |
| |
| def __repr__(self): |
| if self.__microseconds: |
| return "%s(%d, %d, %d)" % ('datetime.' + self.__class__.__name__, |
| self.__days, |
| self.__seconds, |
| self.__microseconds) |
| if self.__seconds: |
| return "%s(%d, %d)" % ('datetime.' + self.__class__.__name__, |
| self.__days, |
| self.__seconds) |
| return "%s(%d)" % ('datetime.' + self.__class__.__name__, self.__days) |
| |
| def __str__(self): |
| mm, ss = divmod(self.__seconds, 60) |
| hh, mm = divmod(mm, 60) |
| s = "%d:%02d:%02d" % (hh, mm, ss) |
| if self.__days: |
| def plural(n): |
| return n, abs(n) != 1 and "s" or "" |
| s = ("%d day%s, " % plural(self.__days)) + s |
| if self.__microseconds: |
| s = s + ".%06d" % self.__microseconds |
| return s |
| |
| days = property(lambda self: self.__days, doc="days") |
| seconds = property(lambda self: self.__seconds, doc="seconds") |
| microseconds = property(lambda self: self.__microseconds, |
| doc="microseconds") |
| |
| def __add__(self, other): |
| if isinstance(other, timedelta): |
| # for CPython compatibility, we cannot use |
| # our __class__ here, but need a real timedelta |
| return timedelta(self.__days + other.__days, |
| self.__seconds + other.__seconds, |
| self.__microseconds + other.__microseconds) |
| return NotImplemented |
| |
| __radd__ = __add__ |
| |
| def __sub__(self, other): |
| if isinstance(other, timedelta): |
| return self + -other |
| return NotImplemented |
| |
| def __rsub__(self, other): |
| if isinstance(other, timedelta): |
| return -self + other |
| return NotImplemented |
| |
| def __neg__(self): |
| # for CPython compatibility, we cannot use |
| # our __class__ here, but need a real timedelta |
| return timedelta(-self.__days, |
| -self.__seconds, |
| -self.__microseconds) |
| |
| def __pos__(self): |
| return self |
| |
| def __abs__(self): |
| if self.__days < 0: |
| return -self |
| else: |
| return self |
| |
| def __mul__(self, other): |
| if isinstance(other, (int, long)): |
| # for CPython compatibility, we cannot use |
| # our __class__ here, but need a real timedelta |
| return timedelta(self.__days * other, |
| self.__seconds * other, |
| self.__microseconds * other) |
| return NotImplemented |
| |
| __rmul__ = __mul__ |
| |
| def __div__(self, other): |
| if isinstance(other, (int, long)): |
| usec = ((self.__days * (24*3600L) + self.__seconds) * 1000000 + |
| self.__microseconds) |
| return timedelta(0, 0, usec // other) |
| return NotImplemented |
| |
| __floordiv__ = __div__ |
| |
| # Comparisons. |
| |
| def __eq__(self, other): |
| if isinstance(other, timedelta): |
| return self.__cmp(other) == 0 |
| else: |
| return False |
| |
| def __ne__(self, other): |
| if isinstance(other, timedelta): |
| return self.__cmp(other) != 0 |
| else: |
| return True |
| |
| def __le__(self, other): |
| if isinstance(other, timedelta): |
| return self.__cmp(other) <= 0 |
| else: |
| _cmperror(self, other) |
| |
| def __lt__(self, other): |
| if isinstance(other, timedelta): |
| return self.__cmp(other) < 0 |
| else: |
| _cmperror(self, other) |
| |
| def __ge__(self, other): |
| if isinstance(other, timedelta): |
| return self.__cmp(other) >= 0 |
| else: |
| _cmperror(self, other) |
| |
| def __gt__(self, other): |
| if isinstance(other, timedelta): |
| return self.__cmp(other) > 0 |
| else: |
| _cmperror(self, other) |
| |
| def __cmp(self, other): |
| assert isinstance(other, timedelta) |
| return cmp(self.__getstate(), other.__getstate()) |
| |
| def __hash__(self): |
| return hash(self.__getstate()) |
| |
| def __nonzero__(self): |
| return (self.__days != 0 or |
| self.__seconds != 0 or |
| self.__microseconds != 0) |
| |
| # Pickle support. |
| |
| __safe_for_unpickling__ = True # For Python 2.2 |
| |
| def __getstate(self): |
| return (self.__days, self.__seconds, self.__microseconds) |
| |
| def __reduce__(self): |
| return (self.__class__, self.__getstate()) |
| |
| timedelta.min = timedelta(-999999999) |
| timedelta.max = timedelta(days=999999999, hours=23, minutes=59, seconds=59, |
| microseconds=999999) |
| timedelta.resolution = timedelta(microseconds=1) |
| |
| class date(object): |
| """Concrete date type. |
| |
| Constructors: |
| |
| __new__() |
| fromtimestamp() |
| today() |
| fromordinal() |
| |
| Operators: |
| |
| __repr__, __str__ |
| __cmp__, __hash__ |
| __add__, __radd__, __sub__ (add/radd only with timedelta arg) |
| |
| Methods: |
| |
| timetuple() |
| toordinal() |
| weekday() |
| isoweekday(), isocalendar(), isoformat() |
| ctime() |
| strftime() |
| |
| Properties (readonly): |
| year, month, day |
| """ |
| |
| def __new__(cls, year, month=None, day=None): |
| """Constructor. |
| |
| Arguments: |
| |
| year, month, day (required, base 1) |
| """ |
| if isinstance(year, str): |
| # Pickle support |
| self = object.__new__(cls) |
| self.__setstate(year) |
| return self |
| _check_date_fields(year, month, day) |
| self = object.__new__(cls) |
| self.__year = year |
| self.__month = month |
| self.__day = day |
| return self |
| |
| # Additional constructors |
| |
| def fromtimestamp(cls, t): |
| "Construct a date from a POSIX timestamp (like time.time())." |
| y, m, d, hh, mm, ss, weekday, jday, dst = _time.localtime(t) |
| return cls(y, m, d) |
| fromtimestamp = classmethod(fromtimestamp) |
| |
| def today(cls): |
| "Construct a date from time.time()." |
| t = _time.time() |
| return cls.fromtimestamp(t) |
| today = classmethod(today) |
| |
| def fromordinal(cls, n): |
| """Contruct a date from a proleptic Gregorian ordinal. |
| |
| January 1 of year 1 is day 1. Only the year, month and day are |
| non-zero in the result. |
| """ |
| y, m, d = _ord2ymd(n) |
| return cls(y, m, d) |
| fromordinal = classmethod(fromordinal) |
| |
| # Conversions to string |
| |
| def __repr__(self): |
| "Convert to formal string, for repr()." |
| return "%s(%d, %d, %d)" % ('datetime.' + self.__class__.__name__, |
| self.__year, |
| self.__month, |
| self.__day) |
| # XXX These shouldn't depend on time.localtime(), because that |
| # clips the usable dates to [1970 .. 2038). At least ctime() is |
| # easily done without using strftime() -- that's better too because |
| # strftime("%c", ...) is locale specific. |
| |
| def ctime(self): |
| "Format a la ctime()." |
| return tmxxx(self.__year, self.__month, self.__day).ctime() |
| |
| def strftime(self, fmt): |
| "Format using strftime()." |
| return _wrap_strftime(self, fmt, self.timetuple()) |
| |
| def isoformat(self): |
| """Return the date formatted according to ISO. |
| |
| This is 'YYYY-MM-DD'. |
| |
| References: |
| - http://www.w3.org/TR/NOTE-datetime |
| - http://www.cl.cam.ac.uk/~mgk25/iso-time.html |
| """ |
| return "%04d-%02d-%02d" % (self.__year, self.__month, self.__day) |
| |
| __str__ = isoformat |
| |
| # Read-only field accessors |
| year = property(lambda self: self.__year, |
| doc="year (%d-%d)" % (MINYEAR, MAXYEAR)) |
| month = property(lambda self: self.__month, doc="month (1-12)") |
| day = property(lambda self: self.__day, doc="day (1-31)") |
| |
| # Standard conversions, __cmp__, __hash__ (and helpers) |
| |
| def timetuple(self): |
| "Return local time tuple compatible with time.localtime()." |
| return _build_struct_time(self.__year, self.__month, self.__day, |
| 0, 0, 0, -1) |
| |
| def toordinal(self): |
| """Return proleptic Gregorian ordinal for the year, month and day. |
| |
| January 1 of year 1 is day 1. Only the year, month and day values |
| contribute to the result. |
| """ |
| return _ymd2ord(self.__year, self.__month, self.__day) |
| |
| def replace(self, year=None, month=None, day=None): |
| """Return a new date with new values for the specified fields.""" |
| if year is None: |
| year = self.__year |
| if month is None: |
| month = self.__month |
| if day is None: |
| day = self.__day |
| _check_date_fields(year, month, day) |
| return date(year, month, day) |
| |
| # Comparisons. |
| |
| def __eq__(self, other): |
| if isinstance(other, date): |
| return self.__cmp(other) == 0 |
| elif hasattr(other, "timetuple"): |
| return NotImplemented |
| else: |
| return False |
| |
| def __ne__(self, other): |
| if isinstance(other, date): |
| return self.__cmp(other) != 0 |
| elif hasattr(other, "timetuple"): |
| return NotImplemented |
| else: |
| return True |
| |
| def __le__(self, other): |
| if isinstance(other, date): |
| return self.__cmp(other) <= 0 |
| elif hasattr(other, "timetuple"): |
| return NotImplemented |
| else: |
| _cmperror(self, other) |
| |
| def __lt__(self, other): |
| if isinstance(other, date): |
| return self.__cmp(other) < 0 |
| elif hasattr(other, "timetuple"): |
| return NotImplemented |
| else: |
| _cmperror(self, other) |
| |
| def __ge__(self, other): |
| if isinstance(other, date): |
| return self.__cmp(other) >= 0 |
| elif hasattr(other, "timetuple"): |
| return NotImplemented |
| else: |
| _cmperror(self, other) |
| |
| def __gt__(self, other): |
| if isinstance(other, date): |
| return self.__cmp(other) > 0 |
| elif hasattr(other, "timetuple"): |
| return NotImplemented |
| else: |
| _cmperror(self, other) |
| |
| def __cmp(self, other): |
| assert isinstance(other, date) |
| y, m, d = self.__year, self.__month, self.__day |
| y2, m2, d2 = other.__year, other.__month, other.__day |
| return cmp((y, m, d), (y2, m2, d2)) |
| |
| def __hash__(self): |
| "Hash." |
| return hash(self.__getstate()) |
| |
| # Computations |
| |
| def _checkOverflow(self, year): |
| if not MINYEAR <= year <= MAXYEAR: |
| raise OverflowError("date +/-: result year %d not in %d..%d" % |
| (year, MINYEAR, MAXYEAR)) |
| |
| def __add__(self, other): |
| "Add a date to a timedelta." |
| if isinstance(other, timedelta): |
| t = tmxxx(self.__year, |
| self.__month, |
| self.__day + other.days) |
| self._checkOverflow(t.year) |
| result = date(t.year, t.month, t.day) |
| return result |
| raise TypeError |
| # XXX Should be 'return NotImplemented', but there's a bug in 2.2... |
| |
| __radd__ = __add__ |
| |
| def __sub__(self, other): |
| """Subtract two dates, or a date and a timedelta.""" |
| if isinstance(other, timedelta): |
| return self + timedelta(-other.days) |
| if isinstance(other, date): |
| days1 = self.toordinal() |
| days2 = other.toordinal() |
| return timedelta(days1 - days2) |
| return NotImplemented |
| |
| def weekday(self): |
| "Return day of the week, where Monday == 0 ... Sunday == 6." |
| return (self.toordinal() + 6) % 7 |
| |
| # Day-of-the-week and week-of-the-year, according to ISO |
| |
| def isoweekday(self): |
| "Return day of the week, where Monday == 1 ... Sunday == 7." |
| # 1-Jan-0001 is a Monday |
| return self.toordinal() % 7 or 7 |
| |
| def isocalendar(self): |
| """Return a 3-tuple containing ISO year, week number, and weekday. |
| |
| The first ISO week of the year is the (Mon-Sun) week |
| containing the year's first Thursday; everything else derives |
| from that. |
| |
| The first week is 1; Monday is 1 ... Sunday is 7. |
| |
| ISO calendar algorithm taken from |
| http://www.phys.uu.nl/~vgent/calendar/isocalendar.htm |
| """ |
| year = self.__year |
| week1monday = _isoweek1monday(year) |
| today = _ymd2ord(self.__year, self.__month, self.__day) |
| # Internally, week and day have origin 0 |
| week, day = divmod(today - week1monday, 7) |
| if week < 0: |
| year -= 1 |
| week1monday = _isoweek1monday(year) |
| week, day = divmod(today - week1monday, 7) |
| elif week >= 52: |
| if today >= _isoweek1monday(year+1): |
| year += 1 |
| week = 0 |
| return year, week+1, day+1 |
| |
| # Pickle support. |
| |
| __safe_for_unpickling__ = True # For Python 2.2 |
| |
| def __getstate(self): |
| yhi, ylo = divmod(self.__year, 256) |
| return ("%c%c%c%c" % (yhi, ylo, self.__month, self.__day), ) |
| |
| def __setstate(self, string): |
| if len(string) != 4 or not (1 <= ord(string[2]) <= 12): |
| raise TypeError("not enough arguments") |
| yhi, ylo, self.__month, self.__day = map(ord, string) |
| self.__year = yhi * 256 + ylo |
| |
| def __reduce__(self): |
| return (self.__class__, self.__getstate()) |
| |
| def __tojava__(self, java_class): |
| from java.lang import Object |
| from java.sql import Date |
| from java.util import Calendar |
| from org.python.core import Py |
| |
| if java_class not in (Calendar, Date, Object): |
| return Py.NoConversion |
| |
| calendar = Calendar.getInstance() |
| calendar.clear() |
| calendar.set(self.year, self.month - 1, self.day) |
| if java_class == Calendar: |
| return calendar |
| else: |
| return Date(calendar.getTimeInMillis()) |
| |
| |
| _date_class = date # so functions w/ args named "date" can get at the class |
| |
| date.min = date(1, 1, 1) |
| date.max = date(9999, 12, 31) |
| date.resolution = timedelta(days=1) |
| |
| class tzinfo(object): |
| """Abstract base class for time zone info classes. |
| |
| Subclasses must override the name(), utcoffset() and dst() methods. |
| """ |
| |
| def tzname(self, dt): |
| "datetime -> string name of time zone." |
| raise NotImplementedError("tzinfo subclass must override tzname()") |
| |
| def utcoffset(self, dt): |
| "datetime -> minutes east of UTC (negative for west of UTC)" |
| raise NotImplementedError("tzinfo subclass must override utcoffset()") |
| |
| def dst(self, dt): |
| """datetime -> DST offset in minutes east of UTC. |
| |
| Return 0 if DST not in effect. utcoffset() must include the DST |
| offset. |
| """ |
| raise NotImplementedError("tzinfo subclass must override dst()") |
| |
| def fromutc(self, dt): |
| "datetime in UTC -> datetime in local time." |
| |
| if not isinstance(dt, datetime): |
| raise TypeError("fromutc() requires a datetime argument") |
| if dt.tzinfo is not self: |
| raise ValueError("dt.tzinfo is not self") |
| |
| dtoff = dt.utcoffset() |
| if dtoff is None: |
| raise ValueError("fromutc() requires a non-None utcoffset() " |
| "result") |
| |
| # See the long comment block at the end of this file for an |
| # explanation of this algorithm. |
| dtdst = dt.dst() |
| if dtdst is None: |
| raise ValueError("fromutc() requires a non-None dst() result") |
| delta = dtoff - dtdst |
| if delta: |
| dt += delta |
| dtdst = dt.dst() |
| if dtdst is None: |
| raise ValueError("fromutc(): dt.dst gave inconsistent " |
| "results; cannot convert") |
| if dtdst: |
| return dt + dtdst |
| else: |
| return dt |
| |
| # Pickle support. |
| |
| __safe_for_unpickling__ = True # For Python 2.2 |
| |
| def __reduce__(self): |
| getinitargs = getattr(self, "__getinitargs__", None) |
| if getinitargs: |
| args = getinitargs() |
| else: |
| args = () |
| getstate = getattr(self, "__getstate__", None) |
| if getstate: |
| state = getstate() |
| else: |
| state = getattr(self, "__dict__", None) or None |
| if state is None: |
| return (self.__class__, args) |
| else: |
| return (self.__class__, args, state) |
| |
| _tzinfo_class = tzinfo # so functions w/ args named "tinfo" can get at it |
| |
| class time(object): |
| """Time with time zone. |
| |
| Constructors: |
| |
| __new__() |
| |
| Operators: |
| |
| __repr__, __str__ |
| __cmp__, __hash__ |
| |
| Methods: |
| |
| strftime() |
| isoformat() |
| utcoffset() |
| tzname() |
| dst() |
| |
| Properties (readonly): |
| hour, minute, second, microsecond, tzinfo |
| """ |
| |
| def __new__(cls, hour=0, minute=0, second=0, microsecond=0, tzinfo=None): |
| """Constructor. |
| |
| Arguments: |
| |
| hour, minute (required) |
| second, microsecond (default to zero) |
| tzinfo (default to None) |
| """ |
| self = object.__new__(cls) |
| if isinstance(hour, str): |
| # Pickle support |
| self.__setstate(hour, minute or None) |
| return self |
| _check_tzinfo_arg(tzinfo) |
| _check_time_fields(hour, minute, second, microsecond) |
| self.__hour = hour |
| self.__minute = minute |
| self.__second = second |
| self.__microsecond = microsecond |
| self._tzinfo = tzinfo |
| return self |
| |
| # Read-only field accessors |
| hour = property(lambda self: self.__hour, doc="hour (0-23)") |
| minute = property(lambda self: self.__minute, doc="minute (0-59)") |
| second = property(lambda self: self.__second, doc="second (0-59)") |
| microsecond = property(lambda self: self.__microsecond, |
| doc="microsecond (0-999999)") |
| tzinfo = property(lambda self: self._tzinfo, doc="timezone info object") |
| |
| # Standard conversions, __hash__ (and helpers) |
| |
| # Comparisons. |
| |
| def __eq__(self, other): |
| if isinstance(other, time): |
| return self.__cmp(other) == 0 |
| else: |
| return False |
| |
| def __ne__(self, other): |
| if isinstance(other, time): |
| return self.__cmp(other) != 0 |
| else: |
| return True |
| |
| def __le__(self, other): |
| if isinstance(other, time): |
| return self.__cmp(other) <= 0 |
| else: |
| _cmperror(self, other) |
| |
| def __lt__(self, other): |
| if isinstance(other, time): |
| return self.__cmp(other) < 0 |
| else: |
| _cmperror(self, other) |
| |
| def __ge__(self, other): |
| if isinstance(other, time): |
| return self.__cmp(other) >= 0 |
| else: |
| _cmperror(self, other) |
| |
| def __gt__(self, other): |
| if isinstance(other, time): |
| return self.__cmp(other) > 0 |
| else: |
| _cmperror(self, other) |
| |
| def __cmp(self, other): |
| assert isinstance(other, time) |
| mytz = self._tzinfo |
| ottz = other._tzinfo |
| myoff = otoff = None |
| |
| if mytz is ottz: |
| base_compare = True |
| else: |
| myoff = self._utcoffset() |
| otoff = other._utcoffset() |
| base_compare = myoff == otoff |
| |
| if base_compare: |
| return cmp((self.__hour, self.__minute, self.__second, |
| self.__microsecond), |
| (other.__hour, other.__minute, other.__second, |
| other.__microsecond)) |
| if myoff is None or otoff is None: |
| # XXX Buggy in 2.2.2. |
| raise TypeError("cannot compare naive and aware times") |
| myhhmm = self.__hour * 60 + self.__minute - myoff |
| othhmm = other.__hour * 60 + other.__minute - otoff |
| return cmp((myhhmm, self.__second, self.__microsecond), |
| (othhmm, other.__second, other.__microsecond)) |
| |
| def __hash__(self): |
| """Hash.""" |
| tzoff = self._utcoffset() |
| if not tzoff: # zero or None |
| return hash(self.__getstate()[0]) |
| h, m = divmod(self.hour * 60 + self.minute - tzoff, 60) |
| if 0 <= h < 24: |
| return hash(time(h, m, self.second, self.microsecond)) |
| return hash((h, m, self.second, self.microsecond)) |
| |
| # Conversion to string |
| |
| def _tzstr(self, sep=":"): |
| """Return formatted timezone offset (+xx:xx) or None.""" |
| off = self._utcoffset() |
| if off is not None: |
| if off < 0: |
| sign = "-" |
| off = -off |
| else: |
| sign = "+" |
| hh, mm = divmod(off, 60) |
| assert 0 <= hh < 24 |
| off = "%s%02d%s%02d" % (sign, hh, sep, mm) |
| return off |
| |
| def __repr__(self): |
| """Convert to formal string, for repr().""" |
| if self.__microsecond != 0: |
| s = ", %d, %d" % (self.__second, self.__microsecond) |
| elif self.__second != 0: |
| s = ", %d" % self.__second |
| else: |
| s = "" |
| s= "%s(%d, %d%s)" % ('datetime.' + self.__class__.__name__, |
| self.__hour, self.__minute, s) |
| if self._tzinfo is not None: |
| assert s[-1:] == ")" |
| s = s[:-1] + ", tzinfo=%r" % self._tzinfo + ")" |
| return s |
| |
| def isoformat(self): |
| """Return the time formatted according to ISO. |
| |
| This is 'HH:MM:SS.mmmmmm+zz:zz', or 'HH:MM:SS+zz:zz' if |
| self.microsecond == 0. |
| """ |
| s = _format_time(self.__hour, self.__minute, self.__second, |
| self.__microsecond) |
| tz = self._tzstr() |
| if tz: |
| s += tz |
| return s |
| |
| __str__ = isoformat |
| |
| def strftime(self, fmt): |
| """Format using strftime(). The date part of the timestamp passed |
| to underlying strftime should not be used. |
| """ |
| # The year must be >= 1900 else Python's strftime implementation |
| # can raise a bogus exception. |
| timetuple = (1900, 1, 1, |
| self.__hour, self.__minute, self.__second, |
| 0, 1, -1) |
| return _wrap_strftime(self, fmt, timetuple) |
| |
| # Timezone functions |
| |
| def utcoffset(self): |
| """Return the timezone offset in minutes east of UTC (negative west of |
| UTC).""" |
| offset = _call_tzinfo_method(self._tzinfo, "utcoffset", None) |
| offset = _check_utc_offset("utcoffset", offset) |
| if offset is not None: |
| offset = timedelta(minutes=offset) |
| return offset |
| |
| # Return an integer (or None) instead of a timedelta (or None). |
| def _utcoffset(self): |
| offset = _call_tzinfo_method(self._tzinfo, "utcoffset", None) |
| offset = _check_utc_offset("utcoffset", offset) |
| return offset |
| |
| def tzname(self): |
| """Return the timezone name. |
| |
| Note that the name is 100% informational -- there's no requirement that |
| it mean anything in particular. For example, "GMT", "UTC", "-500", |
| "-5:00", "EDT", "US/Eastern", "America/New York" are all valid replies. |
| """ |
| name = _call_tzinfo_method(self._tzinfo, "tzname", None) |
| _check_tzname(name) |
| return name |
| |
| def dst(self): |
| """Return 0 if DST is not in effect, or the DST offset (in minutes |
| eastward) if DST is in effect. |
| |
| This is purely informational; the DST offset has already been added to |
| the UTC offset returned by utcoffset() if applicable, so there's no |
| need to consult dst() unless you're interested in displaying the DST |
| info. |
| """ |
| offset = _call_tzinfo_method(self._tzinfo, "dst", None) |
| offset = _check_utc_offset("dst", offset) |
| if offset is not None: |
| offset = timedelta(minutes=offset) |
| return offset |
| |
| def replace(self, hour=None, minute=None, second=None, microsecond=None, |
| tzinfo=True): |
| """Return a new time with new values for the specified fields.""" |
| if hour is None: |
| hour = self.hour |
| if minute is None: |
| minute = self.minute |
| if second is None: |
| second = self.second |
| if microsecond is None: |
| microsecond = self.microsecond |
| if tzinfo is True: |
| tzinfo = self.tzinfo |
| _check_time_fields(hour, minute, second, microsecond) |
| _check_tzinfo_arg(tzinfo) |
| return time(hour, minute, second, microsecond, tzinfo) |
| |
| # Return an integer (or None) instead of a timedelta (or None). |
| def _dst(self): |
| offset = _call_tzinfo_method(self._tzinfo, "dst", None) |
| offset = _check_utc_offset("dst", offset) |
| return offset |
| |
| def __nonzero__(self): |
| if self.second or self.microsecond: |
| return 1 |
| offset = self._utcoffset() or 0 |
| return self.hour * 60 + self.minute - offset != 0 |
| |
| # Pickle support. |
| |
| __safe_for_unpickling__ = True # For Python 2.2 |
| |
| def __getstate(self): |
| us2, us3 = divmod(self.__microsecond, 256) |
| us1, us2 = divmod(us2, 256) |
| basestate = ("%c" * 6) % (self.__hour, self.__minute, self.__second, |
| us1, us2, us3) |
| if self._tzinfo is None: |
| return (basestate,) |
| else: |
| return (basestate, self._tzinfo) |
| |
| def __setstate(self, string, tzinfo): |
| if len(string) != 6 or ord(string[0]) >= 24: |
| raise TypeError("an integer is required") |
| self.__hour, self.__minute, self.__second, us1, us2, us3 = \ |
| map(ord, string) |
| self.__microsecond = (((us1 << 8) | us2) << 8) | us3 |
| self._tzinfo = tzinfo |
| |
| def __reduce__(self): |
| return (time, self.__getstate()) |
| |
| def __tojava__(self, java_class): |
| # TODO, if self.tzinfo is not None, convert time to UTC |
| from java.lang import Object |
| from java.sql import Time |
| from java.util import Calendar |
| from org.python.core import Py |
| |
| if java_class not in (Calendar, Time, Object): |
| return Py.NoConversion |
| |
| calendar = Calendar.getInstance() |
| calendar.clear() |
| calendar.set(Calendar.HOUR_OF_DAY, self.hour) |
| calendar.set(Calendar.MINUTE, self.minute) |
| calendar.set(Calendar.SECOND, self.second) |
| calendar.set(Calendar.MILLISECOND, self.microsecond // 1000) |
| if java_class == Calendar: |
| return calendar |
| else: |
| return Time(calendar.getTimeInMillis()) |
| |
| |
| _time_class = time # so functions w/ args named "time" can get at the class |
| |
| time.min = time(0, 0, 0) |
| time.max = time(23, 59, 59, 999999) |
| time.resolution = timedelta(microseconds=1) |
| |
| class datetime(date): |
| |
| # XXX needs docstrings |
| # See http://www.zope.org/Members/fdrake/DateTimeWiki/TimeZoneInfo |
| |
| def __new__(cls, year, month=None, day=None, hour=0, minute=0, second=0, |
| microsecond=0, tzinfo=None): |
| if isinstance(year, str): |
| # Pickle support |
| self = date.__new__(cls, year[:4]) |
| self.__setstate(year, month) |
| return self |
| _check_tzinfo_arg(tzinfo) |
| _check_time_fields(hour, minute, second, microsecond) |
| self = date.__new__(cls, year, month, day) |
| # XXX This duplicates __year, __month, __day for convenience :-( |
| self.__year = year |
| self.__month = month |
| self.__day = day |
| self.__hour = hour |
| self.__minute = minute |
| self.__second = second |
| self.__microsecond = microsecond |
| self._tzinfo = tzinfo |
| return self |
| |
| # Read-only field accessors |
| hour = property(lambda self: self.__hour, doc="hour (0-23)") |
| minute = property(lambda self: self.__minute, doc="minute (0-59)") |
| second = property(lambda self: self.__second, doc="second (0-59)") |
| microsecond = property(lambda self: self.__microsecond, |
| doc="microsecond (0-999999)") |
| tzinfo = property(lambda self: self._tzinfo, doc="timezone info object") |
| |
| def fromtimestamp(cls, t, tz=None): |
| """Construct a datetime from a POSIX timestamp (like time.time()). |
| |
| A timezone info object may be passed in as well. |
| """ |
| |
| _check_tzinfo_arg(tz) |
| if tz is None: |
| converter = _time.localtime |
| else: |
| converter = _time.gmtime |
| y, m, d, hh, mm, ss, weekday, jday, dst = converter(t) |
| us = int((t % 1.0) * 1000000) |
| |
| if us == 1000001 or us == 999999: |
| us = 0 |
| rounded = True |
| else: |
| rounded = False |
| |
| ss = min(ss, 59) # clamp out leap seconds if the platform has them |
| result = cls(y, m, d, hh, mm, ss, us, tz) |
| if rounded: |
| result += timedelta(seconds=1) |
| if tz is not None: |
| result = tz.fromutc(result) |
| return result |
| fromtimestamp = classmethod(fromtimestamp) |
| |
| def utcfromtimestamp(cls, t): |
| "Construct a UTC datetime from a POSIX timestamp (like time.time())." |
| y, m, d, hh, mm, ss, weekday, jday, dst = _time.gmtime(t) |
| us = int((t % 1.0) * 1000000) |
| ss = min(ss, 59) # clamp out leap seconds if the platform has them |
| return cls(y, m, d, hh, mm, ss, us) |
| utcfromtimestamp = classmethod(utcfromtimestamp) |
| |
| # XXX This is supposed to do better than we *can* do by using time.time(), |
| # XXX if the platform supports a more accurate way. The C implementation |
| # XXX uses gettimeofday on platforms that have it, but that isn't |
| # XXX available from Python. So now() may return different results |
| # XXX across the implementations. |
| def now(cls, tz=None): |
| "Construct a datetime from time.time() and optional time zone info." |
| t = _time.time() |
| return cls.fromtimestamp(t, tz) |
| now = classmethod(now) |
| |
| def utcnow(cls): |
| "Construct a UTC datetime from time.time()." |
| t = _time.time() |
| return cls.utcfromtimestamp(t) |
| utcnow = classmethod(utcnow) |
| |
| def combine(cls, date, time): |
| "Construct a datetime from a given date and a given time." |
| if not isinstance(date, _date_class): |
| raise TypeError("date argument must be a date instance") |
| if not isinstance(time, _time_class): |
| raise TypeError("time argument must be a time instance") |
| return cls(date.year, date.month, date.day, |
| time.hour, time.minute, time.second, time.microsecond, |
| time.tzinfo) |
| combine = classmethod(combine) |
| |
| def strptime(cls, date_string, format): |
| """datetime(year, month, day[, hour[, minute[, second[, microsecond[,tzinfo]]]]]) |
| |
| The year, month and day arguments are required. tzinfo may be None, or an |
| instance of a tzinfo subclass. The remaining arguments may be ints or longs.""" |
| return cls(*(_time.strptime(date_string, format))[0:6]) |
| |
| strptime = classmethod(strptime) |
| |
| def timetuple(self): |
| "Return local time tuple compatible with time.localtime()." |
| dst = self._dst() |
| if dst is None: |
| dst = -1 |
| elif dst: |
| dst = 1 |
| return _build_struct_time(self.year, self.month, self.day, |
| self.hour, self.minute, self.second, |
| dst) |
| |
| def utctimetuple(self): |
| "Return UTC time tuple compatible with time.gmtime()." |
| y, m, d = self.year, self.month, self.day |
| hh, mm, ss = self.hour, self.minute, self.second |
| offset = self._utcoffset() |
| if offset: # neither None nor 0 |
| tm = tmxxx(y, m, d, hh, mm - offset) |
| y, m, d = tm.year, tm.month, tm.day |
| hh, mm = tm.hour, tm.minute |
| return _build_struct_time(y, m, d, hh, mm, ss, 0) |
| |
| def date(self): |
| "Return the date part." |
| return date(self.__year, self.__month, self.__day) |
| |
| def time(self): |
| "Return the time part, with tzinfo None." |
| return time(self.hour, self.minute, self.second, self.microsecond) |
| |
| def timetz(self): |
| "Return the time part, with same tzinfo." |
| return time(self.hour, self.minute, self.second, self.microsecond, |
| self._tzinfo) |
| |
| def replace(self, year=None, month=None, day=None, hour=None, |
| minute=None, second=None, microsecond=None, tzinfo=True): |
| """Return a new datetime with new values for the specified fields.""" |
| if year is None: |
| year = self.year |
| if month is None: |
| month = self.month |
| if day is None: |
| day = self.day |
| if hour is None: |
| hour = self.hour |
| if minute is None: |
| minute = self.minute |
| if second is None: |
| second = self.second |
| if microsecond is None: |
| microsecond = self.microsecond |
| if tzinfo is True: |
| tzinfo = self.tzinfo |
| _check_date_fields(year, month, day) |
| _check_time_fields(hour, minute, second, microsecond) |
| _check_tzinfo_arg(tzinfo) |
| return datetime(year, month, day, hour, minute, second, |
| microsecond, tzinfo) |
| |
| def astimezone(self, tz): |
| if not isinstance(tz, tzinfo): |
| raise TypeError("tz argument must be an instance of tzinfo") |
| |
| mytz = self.tzinfo |
| if mytz is None: |
| raise ValueError("astimezone() requires an aware datetime") |
| |
| if tz is mytz: |
| return self |
| |
| # Convert self to UTC, and attach the new time zone object. |
| myoffset = self.utcoffset() |
| if myoffset is None: |
| raise ValueError("astimezone() requires an aware datetime") |
| utc = (self - myoffset).replace(tzinfo=tz) |
| |
| # Convert from UTC to tz's local time. |
| return tz.fromutc(utc) |
| |
| # Ways to produce a string. |
| |
| def ctime(self): |
| "Format a la ctime()." |
| t = tmxxx(self.__year, self.__month, self.__day, self.__hour, |
| self.__minute, self.__second) |
| return t.ctime() |
| |
| def isoformat(self, sep='T'): |
| """Return the time formatted according to ISO. |
| |
| This is 'YYYY-MM-DD HH:MM:SS.mmmmmm', or 'YYYY-MM-DD HH:MM:SS' if |
| self.microsecond == 0. |
| |
| If self.tzinfo is not None, the UTC offset is also attached, giving |
| 'YYYY-MM-DD HH:MM:SS.mmmmmm+HH:MM' or 'YYYY-MM-DD HH:MM:SS+HH:MM'. |
| |
| Optional argument sep specifies the separator between date and |
| time, default 'T'. |
| """ |
| s = ("%04d-%02d-%02d%c" % (self.__year, self.__month, self.__day, |
| sep) + |
| _format_time(self.__hour, self.__minute, self.__second, |
| self.__microsecond)) |
| off = self._utcoffset() |
| if off is not None: |
| if off < 0: |
| sign = "-" |
| off = -off |
| else: |
| sign = "+" |
| hh, mm = divmod(off, 60) |
| s += "%s%02d:%02d" % (sign, hh, mm) |
| return s |
| |
| def __repr__(self): |
| "Convert to formal string, for repr()." |
| L = [self.__year, self.__month, self.__day, # These are never zero |
| self.__hour, self.__minute, self.__second, self.__microsecond] |
| if L[-1] == 0: |
| del L[-1] |
| if L[-1] == 0: |
| del L[-1] |
| s = ", ".join(map(str, L)) |
| s = "%s(%s)" % ('datetime.' + self.__class__.__name__, s) |
| if self._tzinfo is not None: |
| assert s[-1:] == ")" |
| s = s[:-1] + ", tzinfo=%r" % self._tzinfo + ")" |
| return s |
| |
| def __str__(self): |
| "Convert to string, for str()." |
| return self.isoformat(sep=' ') |
| |
| def utcoffset(self): |
| """Return the timezone offset in minutes east of UTC (negative west of |
| UTC).""" |
| offset = _call_tzinfo_method(self._tzinfo, "utcoffset", self) |
| offset = _check_utc_offset("utcoffset", offset) |
| if offset is not None: |
| offset = timedelta(minutes=offset) |
| return offset |
| |
| # Return an integer (or None) instead of a timedelta (or None). |
| def _utcoffset(self): |
| offset = _call_tzinfo_method(self._tzinfo, "utcoffset", self) |
| offset = _check_utc_offset("utcoffset", offset) |
| return offset |
| |
| def tzname(self): |
| """Return the timezone name. |
| |
| Note that the name is 100% informational -- there's no requirement that |
| it mean anything in particular. For example, "GMT", "UTC", "-500", |
| "-5:00", "EDT", "US/Eastern", "America/New York" are all valid replies. |
| """ |
| name = _call_tzinfo_method(self._tzinfo, "tzname", self) |
| _check_tzname(name) |
| return name |
| |
| def dst(self): |
| """Return 0 if DST is not in effect, or the DST offset (in minutes |
| eastward) if DST is in effect. |
| |
| This is purely informational; the DST offset has already been added to |
| the UTC offset returned by utcoffset() if applicable, so there's no |
| need to consult dst() unless you're interested in displaying the DST |
| info. |
| """ |
| offset = _call_tzinfo_method(self._tzinfo, "dst", self) |
| offset = _check_utc_offset("dst", offset) |
| if offset is not None: |
| offset = timedelta(minutes=offset) |
| return offset |
| |
| # Return an integer (or None) instead of a timedelta (or None).1573 |
| def _dst(self): |
| offset = _call_tzinfo_method(self._tzinfo, "dst", self) |
| offset = _check_utc_offset("dst", offset) |
| return offset |
| |
| # Comparisons. |
| |
| def __eq__(self, other): |
| if isinstance(other, datetime): |
| return self.__cmp(other) == 0 |
| elif hasattr(other, "timetuple") and not isinstance(other, date): |
| return NotImplemented |
| else: |
| return False |
| |
| def __ne__(self, other): |
| if isinstance(other, datetime): |
| return self.__cmp(other) != 0 |
| elif hasattr(other, "timetuple") and not isinstance(other, date): |
| return NotImplemented |
| else: |
| return True |
| |
| def __le__(self, other): |
| if isinstance(other, datetime): |
| return self.__cmp(other) <= 0 |
| elif hasattr(other, "timetuple") and not isinstance(other, date): |
| return NotImplemented |
| else: |
| _cmperror(self, other) |
| |
| def __lt__(self, other): |
| if isinstance(other, datetime): |
| return self.__cmp(other) < 0 |
| elif hasattr(other, "timetuple") and not isinstance(other, date): |
| return NotImplemented |
| else: |
| _cmperror(self, other) |
| |
| def __ge__(self, other): |
| if isinstance(other, datetime): |
| return self.__cmp(other) >= 0 |
| elif hasattr(other, "timetuple") and not isinstance(other, date): |
| return NotImplemented |
| else: |
| _cmperror(self, other) |
| |
| def __gt__(self, other): |
| if isinstance(other, datetime): |
| return self.__cmp(other) > 0 |
| elif hasattr(other, "timetuple") and not isinstance(other, date): |
| return NotImplemented |
| else: |
| _cmperror(self, other) |
| |
| def __cmp(self, other): |
| assert isinstance(other, datetime) |
| mytz = self._tzinfo |
| ottz = other._tzinfo |
| myoff = otoff = None |
| |
| if mytz is ottz: |
| base_compare = True |
| else: |
| if mytz is not None: |
| myoff = self._utcoffset() |
| if ottz is not None: |
| otoff = other._utcoffset() |
| base_compare = myoff == otoff |
| |
| if base_compare: |
| return cmp((self.__year, self.__month, self.__day, |
| self.__hour, self.__minute, self.__second, |
| self.__microsecond), |
| (other.__year, other.__month, other.__day, |
| other.__hour, other.__minute, other.__second, |
| other.__microsecond)) |
| if myoff is None or otoff is None: |
| # XXX Buggy in 2.2.2. |
| raise TypeError("cannot compare naive and aware datetimes") |
| # XXX What follows could be done more efficiently... |
| diff = self - other # this will take offsets into account |
| if diff.days < 0: |
| return -1 |
| return diff and 1 or 0 |
| |
| def __add__(self, other): |
| "Add a datetime and a timedelta." |
| if not isinstance(other, timedelta): |
| return NotImplemented |
| t = tmxxx(self.__year, |
| self.__month, |
| self.__day + other.days, |
| self.__hour, |
| self.__minute, |
| self.__second + other.seconds, |
| self.__microsecond + other.microseconds) |
| self._checkOverflow(t.year) |
| result = datetime(t.year, t.month, t.day, |
| t.hour, t.minute, t.second, |
| t.microsecond, tzinfo=self._tzinfo) |
| return result |
| |
| __radd__ = __add__ |
| |
| def __sub__(self, other): |
| "Subtract two datetimes, or a datetime and a timedelta." |
| if not isinstance(other, datetime): |
| if isinstance(other, timedelta): |
| return self + -other |
| return NotImplemented |
| |
| days1 = self.toordinal() |
| days2 = other.toordinal() |
| secs1 = self.__second + self.__minute * 60 + self.__hour * 3600 |
| secs2 = other.__second + other.__minute * 60 + other.__hour * 3600 |
| base = timedelta(days1 - days2, |
| secs1 - secs2, |
| self.__microsecond - other.__microsecond) |
| if self._tzinfo is other._tzinfo: |
| return base |
| myoff = self._utcoffset() |
| otoff = other._utcoffset() |
| if myoff == otoff: |
| return base |
| if myoff is None or otoff is None: |
| raise TypeError, "cannot mix naive and timezone-aware time" |
| return base + timedelta(minutes = otoff-myoff) |
| |
| def __hash__(self): |
| tzoff = self._utcoffset() |
| if tzoff is None: |
| return hash(self.__getstate()[0]) |
| days = _ymd2ord(self.year, self.month, self.day) |
| seconds = self.hour * 3600 + (self.minute - tzoff) * 60 + self.second |
| return hash(timedelta(days, seconds, self.microsecond)) |
| |
| # Pickle support. |
| |
| __safe_for_unpickling__ = True # For Python 2.2 |
| |
| def __getstate(self): |
| yhi, ylo = divmod(self.__year, 256) |
| us2, us3 = divmod(self.__microsecond, 256) |
| us1, us2 = divmod(us2, 256) |
| basestate = ("%c" * 10) % (yhi, ylo, self.__month, self.__day, |
| self.__hour, self.__minute, self.__second, |
| us1, us2, us3) |
| if self._tzinfo is None: |
| return (basestate,) |
| else: |
| return (basestate, self._tzinfo) |
| |
| def __setstate(self, string, tzinfo): |
| (yhi, ylo, self.__month, self.__day, self.__hour, |
| self.__minute, self.__second, us1, us2, us3) = map(ord, string) |
| self.__year = yhi * 256 + ylo |
| self.__microsecond = (((us1 << 8) | us2) << 8) | us3 |
| self._tzinfo = tzinfo |
| |
| def __reduce__(self): |
| return (self.__class__, self.__getstate()) |
| |
| def __tojava__(self, java_class): |
| # TODO, if self.tzinfo is not None, convert time to UTC |
| from java.lang import Object |
| from java.sql import Timestamp |
| from java.util import Calendar |
| from org.python.core import Py |
| |
| if java_class not in (Calendar, Timestamp, Object): |
| return Py.NoConversion |
| |
| calendar = Calendar.getInstance() |
| calendar.clear() |
| calendar.set(self.year, self.month - 1, self.day, |
| self.hour, self.minute, self.second) |
| |
| if java_class == Calendar: |
| calendar.set(Calendar.MILLISECOND, self.microsecond // 1000) |
| return calendar |
| else: |
| timestamp = Timestamp(calendar.getTimeInMillis()) |
| timestamp.setNanos(self.microsecond * 1000) |
| return timestamp |
| |
| |
| datetime.min = datetime(1, 1, 1) |
| datetime.max = datetime(9999, 12, 31, 23, 59, 59, 999999) |
| datetime.resolution = timedelta(microseconds=1) |
| |
| |
| def _isoweek1monday(year): |
| # Helper to calculate the day number of the Monday starting week 1 |
| # XXX This could be done more efficiently |
| THURSDAY = 3 |
| firstday = _ymd2ord(year, 1, 1) |
| firstweekday = (firstday + 6) % 7 # See weekday() above |
| week1monday = firstday - firstweekday |
| if firstweekday > THURSDAY: |
| week1monday += 7 |
| return week1monday |
| |
| """ |
| Some time zone algebra. For a datetime x, let |
| x.n = x stripped of its timezone -- its naive time. |
| x.o = x.utcoffset(), and assuming that doesn't raise an exception or |
| return None |
| x.d = x.dst(), and assuming that doesn't raise an exception or |
| return None |
| x.s = x's standard offset, x.o - x.d |
| |
| Now some derived rules, where k is a duration (timedelta). |
| |
| 1. x.o = x.s + x.d |
| This follows from the definition of x.s. |
| |
| 2. If x and y have the same tzinfo member, x.s = y.s. |
| This is actually a requirement, an assumption we need to make about |
| sane tzinfo classes. |
| |
| 3. The naive UTC time corresponding to x is x.n - x.o. |
| This is again a requirement for a sane tzinfo class. |
| |
| 4. (x+k).s = x.s |
| This follows from #2, and that datimetimetz+timedelta preserves tzinfo. |
| |
| 5. (x+k).n = x.n + k |
| Again follows from how arithmetic is defined. |
| |
| Now we can explain tz.fromutc(x). Let's assume it's an interesting case |
| (meaning that the various tzinfo methods exist, and don't blow up or return |
| None when called). |
| |
| The function wants to return a datetime y with timezone tz, equivalent to x. |
| x is already in UTC. |
| |
| By #3, we want |
| |
| y.n - y.o = x.n [1] |
| |
| The algorithm starts by attaching tz to x.n, and calling that y. So |
| x.n = y.n at the start. Then it wants to add a duration k to y, so that [1] |
| becomes true; in effect, we want to solve [2] for k: |
| |
| (y+k).n - (y+k).o = x.n [2] |
| |
| By #1, this is the same as |
| |
| (y+k).n - ((y+k).s + (y+k).d) = x.n [3] |
| |
| By #5, (y+k).n = y.n + k, which equals x.n + k because x.n=y.n at the start. |
| Substituting that into [3], |
| |
| x.n + k - (y+k).s - (y+k).d = x.n; the x.n terms cancel, leaving |
| k - (y+k).s - (y+k).d = 0; rearranging, |
| k = (y+k).s - (y+k).d; by #4, (y+k).s == y.s, so |
| k = y.s - (y+k).d |
| |
| On the RHS, (y+k).d can't be computed directly, but y.s can be, and we |
| approximate k by ignoring the (y+k).d term at first. Note that k can't be |
| very large, since all offset-returning methods return a duration of magnitude |
| less than 24 hours. For that reason, if y is firmly in std time, (y+k).d must |
| be 0, so ignoring it has no consequence then. |
| |
| In any case, the new value is |
| |
| z = y + y.s [4] |
| |
| It's helpful to step back at look at [4] from a higher level: it's simply |
| mapping from UTC to tz's standard time. |
| |
| At this point, if |
| |
| z.n - z.o = x.n [5] |
| |
| we have an equivalent time, and are almost done. The insecurity here is |
| at the start of daylight time. Picture US Eastern for concreteness. The wall |
| time jumps from 1:59 to 3:00, and wall hours of the form 2:MM don't make good |
| sense then. The docs ask that an Eastern tzinfo class consider such a time to |
| be EDT (because it's "after 2"), which is a redundant spelling of 1:MM EST |
| on the day DST starts. We want to return the 1:MM EST spelling because that's |
| the only spelling that makes sense on the local wall clock. |
| |
| In fact, if [5] holds at this point, we do have the standard-time spelling, |
| but that takes a bit of proof. We first prove a stronger result. What's the |
| difference between the LHS and RHS of [5]? Let |
| |
| diff = x.n - (z.n - z.o) [6] |
| |
| Now |
| z.n = by [4] |
| (y + y.s).n = by #5 |
| y.n + y.s = since y.n = x.n |
| x.n + y.s = since z and y are have the same tzinfo member, |
| y.s = z.s by #2 |
| x.n + z.s |
| |
| Plugging that back into [6] gives |
| |
| diff = |
| x.n - ((x.n + z.s) - z.o) = expanding |
| x.n - x.n - z.s + z.o = cancelling |
| - z.s + z.o = by #2 |
| z.d |
| |
| So diff = z.d. |
| |
| If [5] is true now, diff = 0, so z.d = 0 too, and we have the standard-time |
| spelling we wanted in the endcase described above. We're done. Contrarily, |
| if z.d = 0, then we have a UTC equivalent, and are also done. |
| |
| If [5] is not true now, diff = z.d != 0, and z.d is the offset we need to |
| add to z (in effect, z is in tz's standard time, and we need to shift the |
| local clock into tz's daylight time). |
| |
| Let |
| |
| z' = z + z.d = z + diff [7] |
| |
| and we can again ask whether |
| |
| z'.n - z'.o = x.n [8] |
| |
| If so, we're done. If not, the tzinfo class is insane, according to the |
| assumptions we've made. This also requires a bit of proof. As before, let's |
| compute the difference between the LHS and RHS of [8] (and skipping some of |
| the justifications for the kinds of substitutions we've done several times |
| already): |
| |
| diff' = x.n - (z'.n - z'.o) = replacing z'.n via [7] |
| x.n - (z.n + diff - z'.o) = replacing diff via [6] |
| x.n - (z.n + x.n - (z.n - z.o) - z'.o) = |
| x.n - z.n - x.n + z.n - z.o + z'.o = cancel x.n |
| - z.n + z.n - z.o + z'.o = cancel z.n |
| - z.o + z'.o = #1 twice |
| -z.s - z.d + z'.s + z'.d = z and z' have same tzinfo |
| z'.d - z.d |
| |
| So z' is UTC-equivalent to x iff z'.d = z.d at this point. If they are equal, |
| we've found the UTC-equivalent so are done. In fact, we stop with [7] and |
| return z', not bothering to compute z'.d. |
| |
| How could z.d and z'd differ? z' = z + z.d [7], so merely moving z' by |
| a dst() offset, and starting *from* a time already in DST (we know z.d != 0), |
| would have to change the result dst() returns: we start in DST, and moving |
| a little further into it takes us out of DST. |
| |
| There isn't a sane case where this can happen. The closest it gets is at |
| the end of DST, where there's an hour in UTC with no spelling in a hybrid |
| tzinfo class. In US Eastern, that's 5:MM UTC = 0:MM EST = 1:MM EDT. During |
| that hour, on an Eastern clock 1:MM is taken as being in standard time (6:MM |
| UTC) because the docs insist on that, but 0:MM is taken as being in daylight |
| time (4:MM UTC). There is no local time mapping to 5:MM UTC. The local |
| clock jumps from 1:59 back to 1:00 again, and repeats the 1:MM hour in |
| standard time. Since that's what the local clock *does*, we want to map both |
| UTC hours 5:MM and 6:MM to 1:MM Eastern. The result is ambiguous |
| in local time, but so it goes -- it's the way the local clock works. |
| |
| When x = 5:MM UTC is the input to this algorithm, x.o=0, y.o=-5 and y.d=0, |
| so z=0:MM. z.d=60 (minutes) then, so [5] doesn't hold and we keep going. |
| z' = z + z.d = 1:MM then, and z'.d=0, and z'.d - z.d = -60 != 0 so [8] |
| (correctly) concludes that z' is not UTC-equivalent to x. |
| |
| Because we know z.d said z was in daylight time (else [5] would have held and |
| we would have stopped then), and we know z.d != z'.d (else [8] would have held |
| and we we have stopped then), and there are only 2 possible values dst() can |
| return in Eastern, it follows that z'.d must be 0 (which it is in the example, |
| but the reasoning doesn't depend on the example -- it depends on there being |
| two possible dst() outcomes, one zero and the other non-zero). Therefore |
| z' must be in standard time, and is the spelling we want in this case. |
| |
| Note again that z' is not UTC-equivalent as far as the hybrid tzinfo class is |
| concerned (because it takes z' as being in standard time rather than the |
| daylight time we intend here), but returning it gives the real-life "local |
| clock repeats an hour" behavior when mapping the "unspellable" UTC hour into |
| tz. |
| |
| When the input is 6:MM, z=1:MM and z.d=0, and we stop at once, again with |
| the 1:MM standard time spelling we want. |
| |
| So how can this break? One of the assumptions must be violated. Two |
| possibilities: |
| |
| 1) [2] effectively says that y.s is invariant across all y belong to a given |
| time zone. This isn't true if, for political reasons or continental drift, |
| a region decides to change its base offset from UTC. |
| |
| 2) There may be versions of "double daylight" time where the tail end of |
| the analysis gives up a step too early. I haven't thought about that |
| enough to say. |
| |
| In any case, it's clear that the default fromutc() is strong enough to handle |
| "almost all" time zones: so long as the standard offset is invariant, it |
| doesn't matter if daylight time transition points change from year to year, or |
| if daylight time is skipped in some years; it doesn't matter how large or |
| small dst() may get within its bounds; and it doesn't even matter if some |
| perverse time zone returns a negative dst()). So a breaking case must be |
| pretty bizarre, and a tzinfo subclass can override fromutc() if it is. |
| """ |
