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+module(datetime)
+"""Concrete date/time and related types.
+
+See http://www.iana.org/time-zones/repository/tz-link.html for
+time zone and DST data sources.
+"""
+
+import time as _time
+import math as _math
+
+def _cmp(x, y):
+ return 0 if x == y else 1 if x > y else -1
+
+MINYEAR = 1
+MAXYEAR = 9999
+_MAXORDINAL = 3652059 # date.max.toordinal()
+
+# 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.
+
+# -1 is a placeholder for indexing purposes.
+_DAYS_IN_MONTH = [-1, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
+
+_DAYS_BEFORE_MONTH = [-1] # -1 is a placeholder for indexing purposes.
+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_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 preceding first day of month."
+ assert 1 <= month <= 12, 'month must be in 1..12'
+ 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."
+ assert 1 <= month <= 12, 'month must be in 1..12'
+ dim = _days_in_month(year, month)
+ assert 1 <= day <= dim, ('day must be in 1..%d' % dim)
+ 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, timespec='auto'):
+ specs = {
+ 'hours': '{:02d}',
+ 'minutes': '{:02d}:{:02d}',
+ 'seconds': '{:02d}:{:02d}:{:02d}',
+ 'milliseconds': '{:02d}:{:02d}:{:02d}.{:03d}',
+ 'microseconds': '{:02d}:{:02d}:{:02d}.{:06d}'
+ }
+
+ if timespec == 'auto':
+ # Skip trailing microseconds when us==0.
+ timespec = 'microseconds' if us else 'seconds'
+ elif timespec == 'milliseconds':
+ us //= 1000
+ try:
+ fmt = specs[timespec]
+ except KeyError:
+ raise ValueError('Unknown timespec value')
+ else:
+ return fmt.format(hh, mm, ss, us)
+
+# Correctly substitute for %z and %Z escapes in strftime formats.
+def _wrap_strftime(object, format, timetuple):
+ # Don't call utcoffset() or tzname() unless actually needed.
+ freplace = None # the string to use for %f
+ 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 == 'f':
+ if freplace is None:
+ freplace = '%06d' % getattr(object,
+ 'microsecond', 0)
+ newformat.append(freplace)
+ elif ch == 'z':
+ if zreplace is None:
+ zreplace = ""
+ if hasattr(object, "utcoffset"):
+ offset = object.utcoffset()
+ if offset is not None:
+ sign = '+'
+ if offset.days < 0:
+ offset = -offset
+ sign = '-'
+ h, m = divmod(offset, timedelta(hours=1))
+ assert not m % timedelta(minutes=1), "whole minute"
+ m //= timedelta(minutes=1)
+ 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)
+
+# 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
+ if not isinstance(offset, timedelta):
+ raise TypeError("tzinfo.%s() must return None "
+ "or timedelta, not '%s'" % (name, type(offset)))
+ if offset.microseconds:
+ raise ValueError("tzinfo.%s() must return a whole number "
+ "of seconds, got %s" % (name, offset))
+ if not -timedelta(1) < offset < timedelta(1):
+ raise ValueError("%s()=%s, must be strictly between "
+ "-timedelta(hours=24) and timedelta(hours=24)" %
+ (name, offset))
+
+def _check_int_field(value):
+ if isinstance(value, int):
+ return value
+ if not isinstance(value, float):
+ try:
+ value = value.__int__()
+ except AttributeError:
+ pass
+ else:
+ if isinstance(value, int):
+ return value
+ raise TypeError('__int__ returned non-int (type %s)' %
+ type(value).__name__)
+ raise TypeError('an integer is required (got type %s)' %
+ type(value).__name__)
+ raise TypeError('integer argument expected, got float')
+
+def _check_date_fields(year, month, day):
+ year = _check_int_field(year)
+ month = _check_int_field(month)
+ day = _check_int_field(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)
+ return year, month, day
+
+def _check_time_fields(hour, minute, second, microsecond, fold):
+ hour = _check_int_field(hour)
+ minute = _check_int_field(minute)
+ second = _check_int_field(second)
+ microsecond = _check_int_field(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)
+ if fold not in (0, 1):
+ raise ValueError('fold must be either 0 or 1', fold)
+ return hour, minute, second, microsecond, fold
+
+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")
+
+def _cmperror(x, y):
+ raise TypeError("can't compare '%s' to '%s'" % (
+ type(x).__name__, type(y).__name__))
+
+def _divide_and_round(a, b):
+ """divide a by b and round result to the nearest integer
+
+ When the ratio is exactly half-way between two integers,
+ the even integer is returned.
+ """
+ # Based on the reference implementation for divmod_near
+ # in Objects/longobject.c.
+ q, r = divmod(a, b)
+ # round up if either r / b > 0.5, or r / b == 0.5 and q is odd.
+ # The expression r / b > 0.5 is equivalent to 2 * r > b if b is
+ # positive, 2 * r < b if b negative.
+ r *= 2
+ greater_than_half = r > b if b > 0 else r < b
+ if greater_than_half or r == b and q % 2 == 1:
+ q += 1
+
+ return q
+
+
+class timedelta:
+ """Represent the difference between two datetime objects.
+
+ Supported operators:
+
+ - add, subtract timedelta
+ - unary plus, minus, abs
+ - compare to timedelta
+ - multiply, divide by int
+
+ 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.
+ """
+ __slots__ = '_days', '_seconds', '_microseconds', '_hashcode'
+
+ def __new__(cls, days=0, seconds=0, microseconds=0,
+ 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 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 == int(days)
+ d = int(days)
+ else:
+ daysecondsfrac = 0.0
+ d = days
+ assert isinstance(daysecondsfrac, float)
+ assert abs(daysecondsfrac) <= 1.0
+ assert isinstance(d, int)
+ assert abs(s) <= 24 * 3600
+ # days isn't referenced again before redefinition
+
+ if isinstance(seconds, float):
+ secondsfrac, seconds = _math.modf(seconds)
+ assert seconds == int(seconds)
+ seconds = int(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)
+ 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 = round(microseconds + usdouble)
+ seconds, microseconds = divmod(microseconds, 1000000)
+ days, seconds = divmod(seconds, 24*3600)
+ d += days
+ s += seconds
+ else:
+ microseconds = int(microseconds)
+ seconds, microseconds = divmod(microseconds, 1000000)
+ days, seconds = divmod(seconds, 24*3600)
+ d += days
+ s += seconds
+ microseconds = round(microseconds + usdouble)
+ assert isinstance(s, int)
+ assert isinstance(microseconds, int)
+ assert abs(s) <= 3 * 24 * 3600
+ assert abs(microseconds) < 3.1e6
+
+ # Just a little bit of carrying possible for microseconds and seconds.
+ seconds, us = divmod(microseconds, 1000000)
+ s += seconds
+ days, s = divmod(s, 24*3600)
+ d += days
+
+ assert isinstance(d, int)
+ assert isinstance(s, int) and 0 <= s < 24*3600
+ assert isinstance(us, int) and 0 <= us < 1000000
+
+ if abs(d) > 999999999:
+ raise OverflowError("timedelta # of days is too large: %d" % d)
+
+ self = object.__new__(cls)
+ self._days = d
+ self._seconds = s
+ self._microseconds = us
+ self._hashcode = -1
+ return self
+
+ def __repr__(self):
+ if self._microseconds:
+ return "%s.%s(%d, %d, %d)" % (self.__class__.__module__,
+ self.__class__.__qualname__,
+ self._days,
+ self._seconds,
+ self._microseconds)
+ if self._seconds:
+ return "%s.%s(%d, %d)" % (self.__class__.__module__,
+ self.__class__.__qualname__,
+ self._days,
+ self._seconds)
+ return "%s.%s(%d)" % (self.__class__.__module__,
+ self.__class__.__qualname__,
+ 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
+
+ def total_seconds(self):
+ """Total seconds in the duration."""
+ return ((self.days * 86400 + self.seconds) * 10**6 +
+ self.microseconds) / 10**6
+
+ # Read-only field accessors
+ @property
+ def days(self):
+ """days"""
+ return self._days
+
+ @property
+ def seconds(self):
+ """seconds"""
+ return self._seconds
+
+ @property
+ def microseconds(self):
+ """microseconds"""
+ return self._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):
+ # 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
+
+ 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):
+ # 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)
+ if isinstance(other, float):
+ usec = self._to_microseconds()
+ a, b = other.as_integer_ratio()
+ return timedelta(0, 0, _divide_and_round(usec * a, b))
+ return NotImplemented
+
+ __rmul__ = __mul__
+
+ def _to_microseconds(self):
+ return ((self._days * (24*3600) + self._seconds) * 1000000 +
+ self._microseconds)
+
+ def __floordiv__(self, other):
+ if not isinstance(other, (int, timedelta)):
+ return NotImplemented
+ usec = self._to_microseconds()
+ if isinstance(other, timedelta):
+ return usec // other._to_microseconds()
+ if isinstance(other, int):
+ return timedelta(0, 0, usec // other)
+
+ def __truediv__(self, other):
+ if not isinstance(other, (int, float, timedelta)):
+ return NotImplemented
+ usec = self._to_microseconds()
+ if isinstance(other, timedelta):
+ return usec / other._to_microseconds()
+ if isinstance(other, int):
+ return timedelta(0, 0, _divide_and_round(usec, other))
+ if isinstance(other, float):
+ a, b = other.as_integer_ratio()
+ return timedelta(0, 0, _divide_and_round(b * usec, a))
+
+ def __mod__(self, other):
+ if isinstance(other, timedelta):
+ r = self._to_microseconds() % other._to_microseconds()
+ return timedelta(0, 0, r)
+ return NotImplemented
+
+ def __divmod__(self, other):
+ if isinstance(other, timedelta):
+ q, r = divmod(self._to_microseconds(),
+ other._to_microseconds())
+ return q, timedelta(0, 0, r)
+ return NotImplemented
+
+ # Comparisons of timedelta objects with other.
+
+ def __eq__(self, other):
+ if isinstance(other, timedelta):
+ return self._cmp(other) == 0
+ else:
+ return False
+
+ 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):
+ if self._hashcode == -1:
+ self._hashcode = hash(self._getstate())
+ return self._hashcode
+
+ def __bool__(self):
+ return (self._days != 0 or
+ self._seconds != 0 or
+ self._microseconds != 0)
+
+ # Pickle support.
+
+ 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:
+ """Concrete date type.
+
+ Constructors:
+
+ __new__()
+ fromtimestamp()
+ today()
+ fromordinal()
+
+ Operators:
+
+ __repr__, __str__
+ __eq__, __le__, __lt__, __ge__, __gt__, __hash__
+ __add__, __radd__, __sub__ (add/radd only with timedelta arg)
+
+ Methods:
+
+ timetuple()
+ toordinal()
+ weekday()
+ isoweekday(), isocalendar(), isoformat()
+ ctime()
+ strftime()
+
+ Properties (readonly):
+ year, month, day
+ """
+ __slots__ = '_year', '_month', '_day', '_hashcode'
+
+ def __new__(cls, year, month=None, day=None):
+ """Constructor.
+
+ Arguments:
+
+ year, month, day (required, base 1)
+ """
+ if month is None and isinstance(year, bytes) and len(year) == 4 and \
+ 1 <= year[2] <= 12:
+ # Pickle support
+ self = object.__new__(cls)
+ self.__setstate(year)
+ self._hashcode = -1
+ return self
+ year, month, day = _check_date_fields(year, month, day)
+ self = object.__new__(cls)
+ self._year = year
+ self._month = month
+ self._day = day
+ self._hashcode = -1
+ return self
+
+ # Additional constructors
+
+ @classmethod
+ 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)
+
+ @classmethod
+ def today(cls):
+ "Construct a date from time.time()."
+ t = _time.time()
+ return cls.fromtimestamp(t)
+
+ @classmethod
+ def fromordinal(cls, n):
+ """Construct 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)
+
+ # Conversions to string
+
+ def __repr__(self):
+ """Convert to formal string, for repr().
+
+ >>> dt = datetime(2010, 1, 1)
+ >>> repr(dt)
+ 'datetime.datetime(2010, 1, 1, 0, 0)'
+
+ >>> dt = datetime(2010, 1, 1, tzinfo=timezone.utc)
+ >>> repr(dt)
+ 'datetime.datetime(2010, 1, 1, 0, 0, tzinfo=datetime.timezone.utc)'
+ """
+ return "%s.%s(%d, %d, %d)" % (self.__class__.__module__,
+ self.__class__.__qualname__,
+ 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):
+ "Return ctime() style string."
+ weekday = self.toordinal() % 7 or 7
+ return "%s %s %2d 00:00:00 %04d" % (
+ _DAYNAMES[weekday],
+ _MONTHNAMES[self._month],
+ self._day, self._year)
+
+ def strftime(self, fmt):
+ "Format using strftime()."
+ return _wrap_strftime(self, fmt, self.timetuple())
+
+ def __format__(self, fmt):
+ if not isinstance(fmt, str):
+ raise TypeError("must be str, not %s" % type(fmt).__name__)
+ if len(fmt) != 0:
+ return self.strftime(fmt)
+ return str(self)
+
+ 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
+ @property
+ def year(self):
+ """year (1-9999)"""
+ return self._year
+
+ @property
+ def month(self):
+ """month (1-12)"""
+ return self._month
+
+ @property
+ def day(self):
+ """day (1-31)"""
+ return self._day
+
+ # Standard conversions, __eq__, __le__, __lt__, __ge__, __gt__,
+ # __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
+ return type(self)(year, month, day)
+
+ # Comparisons of date objects with other.
+
+ def __eq__(self, other):
+ if isinstance(other, date):
+ return self._cmp(other) == 0
+ return NotImplemented
+
+ def __le__(self, other):
+ if isinstance(other, date):
+ return self._cmp(other) <= 0
+ return NotImplemented
+
+ def __lt__(self, other):
+ if isinstance(other, date):
+ return self._cmp(other) < 0
+ return NotImplemented
+
+ def __ge__(self, other):
+ if isinstance(other, date):
+ return self._cmp(other) >= 0
+ return NotImplemented
+
+ def __gt__(self, other):
+ if isinstance(other, date):
+ return self._cmp(other) > 0
+ return NotImplemented
+
+ 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."
+ if self._hashcode == -1:
+ self._hashcode = hash(self._getstate())
+ return self._hashcode
+
+ # Computations
+
+ def __add__(self, other):
+ "Add a date to a timedelta."
+ if isinstance(other, timedelta):
+ o = self.toordinal() + other.days
+ if 0 < o <= _MAXORDINAL:
+ return date.fromordinal(o)
+ raise OverflowError("result out of range")
+ return NotImplemented
+
+ __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
+ (used with permission)
+ """
+ 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.
+
+ def _getstate(self):
+ yhi, ylo = divmod(self._year, 256)
+ return bytes([yhi, ylo, self._month, self._day]),
+
+ def __setstate(self, string):
+ yhi, ylo, self._month, self._day = string
+ self._year = yhi * 256 + ylo
+
+ def __reduce__(self):
+ return (self.__class__, self._getstate())
+
+_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:
+ """Abstract base class for time zone info classes.
+
+ Subclasses must override the name(), utcoffset() and dst() methods.
+ """
+ __slots__ = ()
+
+ 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")
+ return dt + dtdst
+
+ # Pickle support.
+
+ 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
+
+class time:
+ """Time with time zone.
+
+ Constructors:
+
+ __new__()
+
+ Operators:
+
+ __repr__, __str__
+ __eq__, __le__, __lt__, __ge__, __gt__, __hash__
+
+ Methods:
+
+ strftime()
+ isoformat()
+ utcoffset()
+ tzname()
+ dst()
+
+ Properties (readonly):
+ hour, minute, second, microsecond, tzinfo, fold
+ """
+ __slots__ = '_hour', '_minute', '_second', '_microsecond', '_tzinfo', '_hashcode', '_fold'
+
+ def __new__(cls, hour=0, minute=0, second=0, microsecond=0, tzinfo=None, *, fold=0):
+ """Constructor.
+
+ Arguments:
+
+ hour, minute (required)
+ second, microsecond (default to zero)
+ tzinfo (default to None)
+ fold (keyword only, default to zero)
+ """
+ if isinstance(hour, bytes) and len(hour) == 6 and hour[0]&0x7F < 24:
+ # Pickle support
+ self = object.__new__(cls)
+ self.__setstate(hour, minute or None)
+ self._hashcode = -1
+ return self
+ hour, minute, second, microsecond, fold = _check_time_fields(
+ hour, minute, second, microsecond, fold)
+ _check_tzinfo_arg(tzinfo)
+ self = object.__new__(cls)
+ self._hour = hour
+ self._minute = minute
+ self._second = second
+ self._microsecond = microsecond
+ self._tzinfo = tzinfo
+ self._hashcode = -1
+ self._fold = fold
+ return self
+
+ # Read-only field accessors
+ @property
+ def hour(self):
+ """hour (0-23)"""
+ return self._hour
+
+ @property
+ def minute(self):
+ """minute (0-59)"""
+ return self._minute
+
+ @property
+ def second(self):
+ """second (0-59)"""
+ return self._second
+
+ @property
+ def microsecond(self):
+ """microsecond (0-999999)"""
+ return self._microsecond
+
+ @property
+ def tzinfo(self):
+ """timezone info object"""
+ return self._tzinfo
+
+ @property
+ def fold(self):
+ return self._fold
+
+ # Standard conversions, __hash__ (and helpers)
+
+ # Comparisons of time objects with other.
+
+ def __eq__(self, other):
+ if isinstance(other, time):
+ return self._cmp(other, allow_mixed=True) == 0
+ else:
+ return False
+
+ 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, allow_mixed=False):
+ 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:
+ if allow_mixed:
+ return 2 # arbitrary non-zero value
+ else:
+ raise TypeError("cannot compare naive and aware times")
+ myhhmm = self._hour * 60 + self._minute - myoff//timedelta(minutes=1)
+ othhmm = other._hour * 60 + other._minute - otoff//timedelta(minutes=1)
+ return _cmp((myhhmm, self._second, self._microsecond),
+ (othhmm, other._second, other._microsecond))
+
+ def __hash__(self):
+ """Hash."""
+ if self._hashcode == -1:
+ if self.fold:
+ t = self.replace(fold=0)
+ else:
+ t = self
+ tzoff = t.utcoffset()
+ if not tzoff: # zero or None
+ self._hashcode = hash(t._getstate()[0])
+ else:
+ h, m = divmod(timedelta(hours=self.hour, minutes=self.minute) - tzoff,
+ timedelta(hours=1))
+ assert not m % timedelta(minutes=1), "whole minute"
+ m //= timedelta(minutes=1)
+ if 0 <= h < 24:
+ self._hashcode = hash(time(h, m, self.second, self.microsecond))
+ else:
+ self._hashcode = hash((h, m, self.second, self.microsecond))
+ return self._hashcode
+
+ # 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.days < 0:
+ sign = "-"
+ off = -off
+ else:
+ sign = "+"
+ hh, mm = divmod(off, timedelta(hours=1))
+ mm, ss = divmod(mm, timedelta(minutes=1))
+ assert 0 <= hh < 24
+ off = "%s%02d%s%02d" % (sign, hh, sep, mm)
+ if ss:
+ off += ':%02d' % ss.seconds
+ 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.%s(%d, %d%s)" % (self.__class__.__module__,
+ self.__class__.__qualname__,
+ self._hour, self._minute, s)
+ if self._tzinfo is not None:
+ assert s[-1:] == ")"
+ s = s[:-1] + ", tzinfo=%r" % self._tzinfo + ")"
+ if self._fold:
+ assert s[-1:] == ")"
+ s = s[:-1] + ", fold=1)"
+ return s
+
+ def isoformat(self, timespec='auto'):
+ """Return the time formatted according to ISO.
+
+ The full format is 'HH:MM:SS.mmmmmm+zz:zz'. By default, the fractional
+ part is omitted if self.microsecond == 0.
+
+ The optional argument timespec specifies the number of additional
+ terms of the time to include.
+ """
+ s = _format_time(self._hour, self._minute, self._second,
+ self._microsecond, timespec)
+ 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 >= 1000 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)
+
+ def __format__(self, fmt):
+ if not isinstance(fmt, str):
+ raise TypeError("must be str, not %s" % type(fmt).__name__)
+ if len(fmt) != 0:
+ return self.strftime(fmt)
+ return str(self)
+
+ # Timezone functions
+
+ def utcoffset(self):
+ """Return the timezone offset in minutes east of UTC (negative west of
+ UTC)."""
+ if self._tzinfo is None:
+ return None
+ offset = self._tzinfo.utcoffset(None)
+ _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.
+ """
+ if self._tzinfo is None:
+ return None
+ name = 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.
+ """
+ if self._tzinfo is None:
+ return None
+ offset = self._tzinfo.dst(None)
+ _check_utc_offset("dst", offset)
+ return offset
+
+ def replace(self, hour=None, minute=None, second=None, microsecond=None,
+ tzinfo=True, *, fold=None):
+ """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
+ if fold is None:
+ fold = self._fold
+ return type(self)(hour, minute, second, microsecond, tzinfo, fold=fold)
+
+ # Pickle support.
+
+ def _getstate(self, protocol=3):
+ us2, us3 = divmod(self._microsecond, 256)
+ us1, us2 = divmod(us2, 256)
+ h = self._hour
+ if self._fold and protocol > 3:
+ h += 128
+ basestate = bytes([h, 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 tzinfo is not None and not isinstance(tzinfo, _tzinfo_class):
+ raise TypeError("bad tzinfo state arg")
+ h, self._minute, self._second, us1, us2, us3 = string
+ if h > 127:
+ self._fold = 1
+ self._hour = h - 128
+ else:
+ self._fold = 0
+ self._hour = h
+ self._microsecond = (((us1 << 8) | us2) << 8) | us3
+ self._tzinfo = tzinfo
+
+ def __reduce_ex__(self, protocol):
+ return (time, self._getstate(protocol))
+
+ def __reduce__(self):
+ return self.__reduce_ex__(2)
+
+_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):
+ """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.
+ """
+ __slots__ = date.__slots__ + time.__slots__
+
+ def __new__(cls, year, month=None, day=None, hour=0, minute=0, second=0,
+ microsecond=0, tzinfo=None, *, fold=0):
+ if isinstance(year, bytes) and len(year) == 10 and 1 <= year[2]&0x7F <= 12:
+ # Pickle support
+ self = object.__new__(cls)
+ self.__setstate(year, month)
+ self._hashcode = -1
+ return self
+ year, month, day = _check_date_fields(year, month, day)
+ hour, minute, second, microsecond, fold = _check_time_fields(
+ hour, minute, second, microsecond, fold)
+ _check_tzinfo_arg(tzinfo)
+ self = object.__new__(cls)
+ self._year = year
+ self._month = month
+ self._day = day
+ self._hour = hour
+ self._minute = minute
+ self._second = second
+ self._microsecond = microsecond
+ self._tzinfo = tzinfo
+ self._hashcode = -1
+ self._fold = fold
+ return self
+
+ # Read-only field accessors
+ @property
+ def hour(self):
+ """hour (0-23)"""
+ return self._hour
+
+ @property
+ def minute(self):
+ """minute (0-59)"""
+ return self._minute
+
+ @property
+ def second(self):
+ """second (0-59)"""
+ return self._second
+
+ @property
+ def microsecond(self):
+ """microsecond (0-999999)"""
+ return self._microsecond
+
+ @property
+ def tzinfo(self):
+ """timezone info object"""
+ return self._tzinfo
+
+ @property
+ def fold(self):
+ return self._fold
+
+ @classmethod
+ def _fromtimestamp(cls, t, utc, tz):
+ """Construct a datetime from a POSIX timestamp (like time.time()).
+
+ A timezone info object may be passed in as well.
+ """
+ frac, t = _math.modf(t)
+ us = round(frac * 1e6)
+ if us >= 1000000:
+ t += 1
+ us -= 1000000
+ elif us < 0:
+ t -= 1
+ us += 1000000
+
+ converter = _time.gmtime if utc else _time.localtime
+ y, m, d, hh, mm, ss, weekday, jday, dst = converter(t)
+ ss = min(ss, 59) # clamp out leap seconds if the platform has them
+ result = cls(y, m, d, hh, mm, ss, us, tz)
+ if tz is None:
+ # As of version 2015f max fold in IANA database is
+ # 23 hours at 1969-09-30 13:00:00 in Kwajalein.
+ # Let's probe 24 hours in the past to detect a transition:
+ max_fold_seconds = 24 * 3600
+ y, m, d, hh, mm, ss = converter(t - max_fold_seconds)[:6]
+ probe1 = cls(y, m, d, hh, mm, ss, us, tz)
+ trans = result - probe1 - timedelta(0, max_fold_seconds)
+ if trans.days < 0:
+ y, m, d, hh, mm, ss = converter(t + trans // timedelta(0, 1))[:6]
+ probe2 = cls(y, m, d, hh, mm, ss, us, tz)
+ if probe2 == result:
+ result._fold = 1
+ else:
+ result = tz.fromutc(result)
+ return result
+
+ @classmethod
+ 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)
+
+ return cls._fromtimestamp(t, tz is not None, tz)
+
+ @classmethod
+ def utcfromtimestamp(cls, t):
+ """Construct a naive UTC datetime from a POSIX timestamp."""
+ return cls._fromtimestamp(t, True, None)
+
+ @classmethod
+ def now(cls, tz=None):
+ "Construct a datetime from time.time() and optional time zone info."
+ t = _time.time()
+ return cls.fromtimestamp(t, tz)
+
+ @classmethod
+ def utcnow(cls):
+ "Construct a UTC datetime from time.time()."
+ t = _time.time()
+ return cls.utcfromtimestamp(t)
+
+ @classmethod
+ def combine(cls, date, time, tzinfo=True):
+ "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")
+ if tzinfo is True:
+ tzinfo = time.tzinfo
+ return cls(date.year, date.month, date.day,
+ time.hour, time.minute, time.second, time.microsecond,
+ tzinfo, fold=time.fold)
+
+ def timetuple(self):
+ "Return local time tuple compatible with time.localtime()."
+ dst = self.dst()
+ if dst is None:
+ dst = -1
+ elif dst:
+ dst = 1
+ else:
+ dst = 0
+ return _build_struct_time(self.year, self.month, self.day,
+ self.hour, self.minute, self.second,
+ dst)
+
+ def _mktime(self):
+ """Return integer POSIX timestamp."""
+ epoch = datetime(1970, 1, 1)
+ max_fold_seconds = 24 * 3600
+ t = (self - epoch) // timedelta(0, 1)
+ def local(u):
+ y, m, d, hh, mm, ss = _time.localtime(u)[:6]
+ return (datetime(y, m, d, hh, mm, ss) - epoch) // timedelta(0, 1)
+
+ # Our goal is to solve t = local(u) for u.
+ a = local(t) - t
+ u1 = t - a
+ t1 = local(u1)
+ if t1 == t:
+ # We found one solution, but it may not be the one we need.
+ # Look for an earlier solution (if `fold` is 0), or a
+ # later one (if `fold` is 1).
+ u2 = u1 + (-max_fold_seconds, max_fold_seconds)[self.fold]
+ b = local(u2) - u2
+ if a == b:
+ return u1
+ else:
+ b = t1 - u1
+ assert a != b
+ u2 = t - b
+ t2 = local(u2)
+ if t2 == t:
+ return u2
+ if t1 == t:
+ return u1
+ # We have found both offsets a and b, but neither t - a nor t - b is
+ # a solution. This means t is in the gap.
+ return (max, min)[self.fold](u1, u2)
+
+
+ def timestamp(self):
+ "Return POSIX timestamp as float"
+ if self._tzinfo is None:
+ s = self._mktime()
+ return s + self.microsecond / 1e6
+ else:
+ return (self - _EPOCH).total_seconds()
+
+ def utctimetuple(self):
+ "Return UTC time tuple compatible with time.gmtime()."
+ offset = self.utcoffset()
+ if offset:
+ self -= offset
+ y, m, d = self.year, self.month, self.day
+ hh, mm, ss = self.hour, self.minute, self.second
+ 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, fold=self.fold)
+
+ def timetz(self):
+ "Return the time part, with same tzinfo."
+ return time(self.hour, self.minute, self.second, self.microsecond,
+ self._tzinfo, fold=self.fold)
+
+ def replace(self, year=None, month=None, day=None, hour=None,
+ minute=None, second=None, microsecond=None, tzinfo=True,
+ *, fold=None):
+ """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
+ if fold is None:
+ fold = self.fold
+ return type(self)(year, month, day, hour, minute, second,
+ microsecond, tzinfo, fold=fold)
+
+ def _local_timezone(self):
+ if self.tzinfo is None:
+ ts = self._mktime()
+ else:
+ ts = (self - _EPOCH) // timedelta(seconds=1)
+ localtm = _time.localtime(ts)
+ local = datetime(*localtm[:6])
+ try:
+ # Extract TZ data if available
+ gmtoff = localtm.tm_gmtoff
+ zone = localtm.tm_zone
+ except AttributeError:
+ delta = local - datetime(*_time.gmtime(ts)[:6])
+ zone = _time.strftime('%Z', localtm)
+ tz = timezone(delta, zone)
+ else:
+ tz = timezone(timedelta(seconds=gmtoff), zone)
+ return tz
+
+ def astimezone(self, tz=None):
+ if tz is None:
+ tz = self._local_timezone()
+ elif not isinstance(tz, tzinfo):
+ raise TypeError("tz argument must be an instance of tzinfo")
+
+ mytz = self.tzinfo
+ if mytz is None:
+ mytz = self._local_timezone()
+
+ if tz is mytz:
+ return self
+
+ # Convert self to UTC, and attach the new time zone object.
+ myoffset = mytz.utcoffset(self)
+ 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):
+ "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)
+
+ def isoformat(self, sep='T', timespec='auto'):
+ """Return the time formatted according to ISO.
+
+ The full format looks like 'YYYY-MM-DD HH:MM:SS.mmmmmm'.
+ By default, the fractional part is omitted if self.microsecond == 0.
+
+ If self.tzinfo is not None, the UTC offset is also attached, giving
+ giving a full format of 'YYYY-MM-DD HH:MM:SS.mmmmmm+HH:MM'.
+
+ Optional argument sep specifies the separator between date and
+ time, default 'T'.
+
+ The optional argument timespec specifies the number of additional
+ terms of the time to include.
+ """
+ s = ("%04d-%02d-%02d%c" % (self._year, self._month, self._day, sep) +
+ _format_time(self._hour, self._minute, self._second,
+ self._microsecond, timespec))
+
+ off = self.utcoffset()
+ if off is not None:
+ if off.days < 0:
+ sign = "-"
+ off = -off
+ else:
+ sign = "+"
+ hh, mm = divmod(off, timedelta(hours=1))
+ mm, ss = divmod(mm, timedelta(minutes=1))
+ s += "%s%02d:%02d" % (sign, hh, mm)
+ if ss:
+ assert not ss.microseconds
+ s += ":%02d" % ss.seconds
+ 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 = "%s.%s(%s)" % (self.__class__.__module__,
+ self.__class__.__qualname__,
+ ", ".join(map(str, L)))
+ if self._tzinfo is not None:
+ assert s[-1:] == ")"
+ s = s[:-1] + ", tzinfo=%r" % self._tzinfo + ")"
+ if self._fold:
+ assert s[-1:] == ")"
+ s = s[:-1] + ", fold=1)"
+ return s
+
+ def __str__(self):
+ "Convert to string, for str()."
+ return self.isoformat(sep=' ')
+
+ @classmethod
+ def strptime(cls, date_string, format):
+ 'string, format -> new datetime parsed from a string (like time.strptime()).'
+ import _strptime
+ return _strptime._strptime_datetime(cls, date_string, format)
+
+ def utcoffset(self):
+ """Return the timezone offset in minutes east of UTC (negative west of
+ UTC)."""
+ if self._tzinfo is None:
+ return None
+ offset = self._tzinfo.utcoffset(self)
+ _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.
+ """
+ if self._tzinfo is None:
+ return None
+ name = 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.
+ """
+ if self._tzinfo is None:
+ return None
+ offset = self._tzinfo.dst(self)
+ _check_utc_offset("dst", offset)
+ return offset
+
+ # Comparisons of datetime objects with other.
+
+ def __eq__(self, other):
+ if isinstance(other, datetime):
+ return self._cmp(other, allow_mixed=True) == 0
+ elif not isinstance(other, date):
+ return NotImplemented
+ else:
+ return False
+
+ def __le__(self, other):
+ if isinstance(other, datetime):
+ return self._cmp(other) <= 0
+ elif not isinstance(other, date):
+ return NotImplemented
+ else:
+ _cmperror(self, other)
+
+ def __lt__(self, other):
+ if isinstance(other, datetime):
+ return self._cmp(other) < 0
+ elif not isinstance(other, date):
+ return NotImplemented
+ else:
+ _cmperror(self, other)
+
+ def __ge__(self, other):
+ if isinstance(other, datetime):
+ return self._cmp(other) >= 0
+ elif not isinstance(other, date):
+ return NotImplemented
+ else:
+ _cmperror(self, other)
+
+ def __gt__(self, other):
+ if isinstance(other, datetime):
+ return self._cmp(other) > 0
+ elif not isinstance(other, date):
+ return NotImplemented
+ else:
+ _cmperror(self, other)
+
+ def _cmp(self, other, allow_mixed=False):
+ assert isinstance(other, datetime)
+ mytz = self._tzinfo
+ ottz = other._tzinfo
+ myoff = otoff = None
+
+ if mytz is ottz:
+ base_compare = True
+ else:
+ myoff = self.utcoffset()
+ otoff = other.utcoffset()
+ # Assume that allow_mixed means that we are called from __eq__
+ if allow_mixed:
+ if myoff != self.replace(fold=not self.fold).utcoffset():
+ return 2
+ if otoff != other.replace(fold=not other.fold).utcoffset():
+ return 2
+ 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:
+ if allow_mixed:
+ return 2 # arbitrary non-zero value
+ else:
+ 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
+ delta = timedelta(self.toordinal(),
+ hours=self._hour,
+ minutes=self._minute,
+ seconds=self._second,
+ microseconds=self._microsecond)
+ delta += other
+ hour, rem = divmod(delta.seconds, 3600)
+ minute, second = divmod(rem, 60)
+ if 0 < delta.days <= _MAXORDINAL:
+ return datetime.combine(date.fromordinal(delta.days),
+ time(hour, minute, second,
+ delta.microseconds,
+ tzinfo=self._tzinfo))
+ raise OverflowError("result out of range")
+
+ __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 + otoff - myoff
+
+ def __hash__(self):
+ if self._hashcode == -1:
+ if self.fold:
+ t = self.replace(fold=0)
+ else:
+ t = self
+ tzoff = t.utcoffset()
+ if tzoff is None:
+ self._hashcode = hash(t._getstate()[0])
+ else:
+ days = _ymd2ord(self.year, self.month, self.day)
+ seconds = self.hour * 3600 + self.minute * 60 + self.second
+ self._hashcode = hash(timedelta(days, seconds, self.microsecond) - tzoff)
+ return self._hashcode
+
+ # Pickle support.
+
+ def _getstate(self, protocol=3):
+ yhi, ylo = divmod(self._year, 256)
+ us2, us3 = divmod(self._microsecond, 256)
+ us1, us2 = divmod(us2, 256)
+ m = self._month
+ if self._fold and protocol > 3:
+ m += 128
+ basestate = bytes([yhi, ylo, m, 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):
+ if tzinfo is not None and not isinstance(tzinfo, _tzinfo_class):
+ raise TypeError("bad tzinfo state arg")
+ (yhi, ylo, m, self._day, self._hour,
+ self._minute, self._second, us1, us2, us3) = string
+ if m > 127:
+ self._fold = 1
+ self._month = m - 128
+ else:
+ self._fold = 0
+ self._month = m
+ self._year = yhi * 256 + ylo
+ self._microsecond = (((us1 << 8) | us2) << 8) | us3
+ self._tzinfo = tzinfo
+
+ def __reduce_ex__(self, protocol):
+ return (self.__class__, self._getstate(protocol))
+
+ def __reduce__(self):
+ return self.__reduce_ex__(2)
+
+
+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
+
+class timezone(tzinfo):
+ __slots__ = '_offset', '_name'
+
+ # Sentinel value to disallow None
+ _Omitted = object()
+ def __new__(cls, offset, name=_Omitted):
+ if not isinstance(offset, timedelta):
+ raise TypeError("offset must be a timedelta")
+ if name is cls._Omitted:
+ if not offset:
+ return cls.utc
+ name = None
+ elif not isinstance(name, str):
+ raise TypeError("name must be a string")
+ if not cls._minoffset <= offset <= cls._maxoffset:
+ raise ValueError("offset must be a timedelta "
+ "strictly between -timedelta(hours=24) and "
+ "timedelta(hours=24).")
+ if (offset.microseconds != 0 or offset.seconds % 60 != 0):
+ raise ValueError("offset must be a timedelta "
+ "representing a whole number of minutes")
+ return cls._create(offset, name)
+
+ @classmethod
+ def _create(cls, offset, name=None):
+ self = tzinfo.__new__(cls)
+ self._offset = offset
+ self._name = name
+ return self
+
+ def __getinitargs__(self):
+ """pickle support"""
+ if self._name is None:
+ return (self._offset,)
+ return (self._offset, self._name)
+
+ def __eq__(self, other):
+ if type(other) != timezone:
+ return False
+ return self._offset == other._offset
+
+ def __hash__(self):
+ return hash(self._offset)
+
+ def __repr__(self):
+ """Convert to formal string, for repr().
+
+ >>> tz = timezone.utc
+ >>> repr(tz)
+ 'datetime.timezone.utc'
+ >>> tz = timezone(timedelta(hours=-5), 'EST')
+ >>> repr(tz)
+ "datetime.timezone(datetime.timedelta(-1, 68400), 'EST')"
+ """
+ if self is self.utc:
+ return 'datetime.timezone.utc'
+ if self._name is None:
+ return "%s.%s(%r)" % (self.__class__.__module__,
+ self.__class__.__qualname__,
+ self._offset)
+ return "%s.%s(%r, %r)" % (self.__class__.__module__,
+ self.__class__.__qualname__,
+ self._offset, self._name)
+
+ def __str__(self):
+ return self.tzname(None)
+
+ def utcoffset(self, dt):
+ if isinstance(dt, datetime) or dt is None:
+ return self._offset
+ raise TypeError("utcoffset() argument must be a datetime instance"
+ " or None")
+
+ def tzname(self, dt):
+ if isinstance(dt, datetime) or dt is None:
+ if self._name is None:
+ return self._name_from_offset(self._offset)
+ return self._name
+ raise TypeError("tzname() argument must be a datetime instance"
+ " or None")
+
+ def dst(self, dt):
+ if isinstance(dt, datetime) or dt is None:
+ return None
+ raise TypeError("dst() argument must be a datetime instance"
+ " or None")
+
+ def fromutc(self, dt):
+ if isinstance(dt, datetime):
+ if dt.tzinfo is not self:
+ raise ValueError("fromutc: dt.tzinfo "
+ "is not self")
+ return dt + self._offset
+ raise TypeError("fromutc() argument must be a datetime instance"
+ " or None")
+
+ _maxoffset = timedelta(hours=23, minutes=59)
+ _minoffset = -_maxoffset
+
+ @staticmethod
+ def _name_from_offset(delta):
+ if not delta:
+ return 'UTC'
+ if delta < timedelta(0):
+ sign = '-'
+ delta = -delta
+ else:
+ sign = '+'
+ hours, rest = divmod(delta, timedelta(hours=1))
+ minutes = rest // timedelta(minutes=1)
+ return 'UTC{}{:02d}:{:02d}'.format(sign, hours, minutes)
+
+timezone.utc = timezone._create(timedelta(0))
+timezone.min = timezone._create(timezone._minoffset)
+timezone.max = timezone._create(timezone._maxoffset)
+_EPOCH = datetime(1970, 1, 1, tzinfo=timezone.utc)
+
+# 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 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.
+
+try:
+ from _datetime import *
+except ImportError:
+ pass
+else:
+ # Clean up unused names
+ del (_DAYNAMES, _DAYS_BEFORE_MONTH, _DAYS_IN_MONTH, _DI100Y, _DI400Y,
+ _DI4Y, _EPOCH, _MAXORDINAL, _MONTHNAMES, _build_struct_time,
+ _check_date_fields, _check_int_field, _check_time_fields,
+ _check_tzinfo_arg, _check_tzname, _check_utc_offset, _cmp, _cmperror,
+ _date_class, _days_before_month, _days_before_year, _days_in_month,
+ _format_time, _is_leap, _isoweek1monday, _math, _ord2ymd,
+ _time, _time_class, _tzinfo_class, _wrap_strftime, _ymd2ord,
+ _divide_and_round)
+ # XXX Since import * above excludes names that start with _,
+ # docstring does not get overwritten. In the future, it may be
+ # appropriate to maintain a single module level docstring and
+ # remove the following line.
+ from _datetime import __doc__