diff env/lib/python3.7/site-packages/future/backports/datetime.py @ 5:9b1c78e6ba9c draft default tip

"planemo upload commit 6c0a8142489327ece472c84e558c47da711a9142"
author shellac
date Mon, 01 Jun 2020 08:59:25 -0400
parents 79f47841a781
children
line wrap: on
line diff
--- a/env/lib/python3.7/site-packages/future/backports/datetime.py	Thu May 14 16:47:39 2020 -0400
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,2152 +0,0 @@
-"""Concrete date/time and related types.
-
-See http://www.iana.org/time-zones/repository/tz-link.html for
-time zone and DST data sources.
-"""
-from __future__ import division
-from __future__ import unicode_literals
-from __future__ import print_function
-from __future__ import absolute_import
-from future.builtins import str
-from future.builtins import bytes
-from future.builtins import map
-from future.builtins import round
-from future.builtins import int
-from future.builtins import object
-from future.utils import native_str, PY2
-
-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.
-
-_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_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):
-    # 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):
-    # 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)
-
-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
-    if not isinstance(offset, timedelta):
-        raise TypeError("tzinfo.%s() must return None "
-                        "or timedelta, not '%s'" % (name, type(offset)))
-    if offset % timedelta(minutes=1) or offset.microseconds:
-        raise ValueError("tzinfo.%s() must return a whole number "
-                         "of minutes, got %s" % (name, offset))
-    if not -timedelta(1) < offset < timedelta(1):
-        raise ValueError("%s()=%s, must be must be strictly between"
-                         " -timedelta(hours=24) and timedelta(hours=24)"
-                         % (name, offset))
-
-def _check_date_fields(year, month, day):
-    if not isinstance(year, int):
-        raise TypeError('int expected')
-    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 isinstance(hour, int):
-        raise TypeError('int expected')
-    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")
-
-def _cmperror(x, y):
-    raise TypeError("can't compare '%s' to '%s'" % (
-                    type(x).__name__, type(y).__name__))
-
-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
-
-    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'
-
-    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 += usdouble
-            microseconds = round(microseconds, 0)
-            seconds, microseconds = divmod(microseconds, 1e6)
-            assert microseconds == int(microseconds)
-            assert seconds == int(seconds)
-            days, seconds = divmod(seconds, 24.*3600.)
-            assert days == int(days)
-            assert seconds == int(seconds)
-            d += int(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, 0)
-        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)
-        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
-
-    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):
-            a, b = other.as_integer_ratio()
-            return self * 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, usec / other)
-        if isinstance(other, float):
-            a, b = other.as_integer_ratio()
-            return timedelta(0, 0, 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 __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 __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(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
-    """
-    __slots__ = '_year', '_month', '_day'
-
-    def __new__(cls, year, month=None, day=None):
-        """Constructor.
-
-        Arguments:
-
-        year, month, day (required, base 1)
-        """
-        if (isinstance(year, bytes) and len(year) == 4 and
-            1 <= year[2] <= 12 and month is None):  # Month is sane
-            # 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
-
-    @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):
-        """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)
-
-    # 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(%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):
-        "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 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, __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 of date objects with other.
-
-    def __eq__(self, other):
-        if isinstance(other, date):
-            return self._cmp(other) == 0
-        return NotImplemented
-
-    def __ne__(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."
-        return hash(self._getstate())
-
-    # 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
-        """
-        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):
-        if len(string) != 4 or not (1 <= string[2] <= 12):
-            raise TypeError("not enough arguments")
-        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(object):
-    """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(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, bytes) and len(hour) == 6:
-            # 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
-    @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
-
-    # 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 __ne__(self, other):
-        if isinstance(other, time):
-            return self._cmp(other, allow_mixed=True) != 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, 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."""
-        tzoff = self.utcoffset()
-        if not tzoff: # zero or None
-            return hash(self._getstate()[0])
-        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:
-            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.days < 0:
-                sign = "-"
-                off = -off
-            else:
-                sign = "+"
-            hh, mm = divmod(off, timedelta(hours=1))
-            assert not mm % timedelta(minutes=1), "whole minute"
-            mm //= timedelta(minutes=1)
-            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 >= 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 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):
-        """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)
-
-    def __bool__(self):
-        if self.second or self.microsecond:
-            return True
-        offset = self.utcoffset() or timedelta(0)
-        return timedelta(hours=self.hour, minutes=self.minute) != offset
-
-    # Pickle support.
-
-    def _getstate(self):
-        us2, us3 = divmod(self._microsecond, 256)
-        us1, us2 = divmod(us2, 256)
-        basestate = bytes([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 string[0] >= 24:
-            raise TypeError("an integer is required")
-        (self._hour, self._minute, self._second,
-         us1, us2, us3) = string
-        self._microsecond = (((us1 << 8) | us2) << 8) | us3
-        if tzinfo is None or isinstance(tzinfo, _tzinfo_class):
-            self._tzinfo = tzinfo
-        else:
-            raise TypeError("bad tzinfo state arg %r" % tzinfo)
-
-    def __reduce__(self):
-        return (time, self._getstate())
-
-_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__ + (
-        '_hour', '_minute', '_second',
-        '_microsecond', '_tzinfo')
-    def __new__(cls, year, month=None, day=None, hour=0, minute=0, second=0,
-                microsecond=0, tzinfo=None):
-        if isinstance(year, bytes) and len(year) == 10:
-            # 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)
-        self._hour = hour
-        self._minute = minute
-        self._second = second
-        self._microsecond = microsecond
-        self._tzinfo = tzinfo
-        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
-
-    @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)
-
-        converter = _time.localtime if tz is None else _time.gmtime
-
-        t, frac = divmod(t, 1.0)
-        us = int(frac * 1e6)
-
-        # If timestamp is less than one microsecond smaller than a
-        # full second, us can be rounded up to 1000000.  In this case,
-        # roll over to seconds, otherwise, ValueError is raised
-        # by the constructor.
-        if us == 1000000:
-            t += 1
-            us = 0
-        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 not None:
-            result = tz.fromutc(result)
-        return result
-
-    @classmethod
-    def utcfromtimestamp(cls, t):
-        "Construct a UTC datetime from a POSIX timestamp (like time.time())."
-        t, frac = divmod(t, 1.0)
-        us = int(frac * 1e6)
-
-        # If timestamp is less than one microsecond smaller than a
-        # full second, us can be rounded up to 1000000.  In this case,
-        # roll over to seconds, otherwise, ValueError is raised
-        # by the constructor.
-        if us == 1000000:
-            t += 1
-            us = 0
-        y, m, d, hh, mm, ss, weekday, jday, dst = _time.gmtime(t)
-        ss = min(ss, 59)    # clamp out leap seconds if the platform has them
-        return cls(y, m, d, hh, mm, ss, us)
-
-    # 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.
-    @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):
-        "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)
-
-    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 timestamp(self):
-        "Return POSIX timestamp as float"
-        if self._tzinfo is None:
-            return _time.mktime((self.year, self.month, self.day,
-                                 self.hour, self.minute, self.second,
-                                 -1, -1, -1)) + 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)
-
-    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=None):
-        if tz is None:
-            if self.tzinfo is None:
-                raise ValueError("astimezone() requires an aware datetime")
-            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:
-                # Compute UTC offset and compare with the value implied
-                # by tm_isdst.  If the values match, use the zone name
-                # implied by tm_isdst.
-                delta = local - datetime(*_time.gmtime(ts)[:6])
-                dst = _time.daylight and localtm.tm_isdst > 0
-                gmtoff = -(_time.altzone if dst else _time.timezone)
-                if delta == timedelta(seconds=gmtoff):
-                    tz = timezone(delta, _time.tzname[dst])
-                else:
-                    tz = timezone(delta)
-            else:
-                tz = timezone(timedelta(seconds=gmtoff), zone)
-
-        elif 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):
-        "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'):
-        """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.days < 0:
-                sign = "-"
-                off = -off
-            else:
-                sign = "+"
-            hh, mm = divmod(off, timedelta(hours=1))
-            assert not mm % timedelta(minutes=1), "whole minute"
-            mm //= timedelta(minutes=1)
-            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=' ')
-
-    @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.
-        """
-        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.
-        """
-        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 __ne__(self, other):
-        if isinstance(other, datetime):
-            return self._cmp(other, allow_mixed=True) != 0
-        elif not isinstance(other, date):
-            return NotImplemented
-        else:
-            return True
-
-    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()
-            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):
-        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 * 60 + self.second
-        return hash(timedelta(days, seconds, self.microsecond) - tzoff)
-
-    # Pickle support.
-
-    def _getstate(self):
-        yhi, ylo = divmod(self._year, 256)
-        us2, us3 = divmod(self._microsecond, 256)
-        us1, us2 = divmod(us2, 256)
-        basestate = bytes([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) = string
-        self._year = yhi * 256 + ylo
-        self._microsecond = (((us1 << 8) | us2) << 8) | us3
-        if tzinfo is None or isinstance(tzinfo, _tzinfo_class):
-            self._tzinfo = tzinfo
-        else:
-            raise TypeError("bad tzinfo state arg %r" % tzinfo)
-
-    def __reduce__(self):
-        return (self.__class__, self._getstate())
-
-
-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):
-            ###
-            # For Python-Future:
-            if PY2 and isinstance(name, native_str):
-                name = name.decode()
-            else:
-                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(%r)" % ('datetime.' + self.__class__.__name__,
-                               self._offset)
-        return "%s(%r, %r)" % ('datetime.' + self.__class__.__name__,
-                               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 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, _MAXORDINAL, _MONTHNAMES,
-         _build_struct_time, _call_tzinfo_method, _check_date_fields,
-         _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)
-    # 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__