mirror of https://github.com/python/cpython
1488 lines
50 KiB
TeX
1488 lines
50 KiB
TeX
% XXX what order should the types be discussed in?
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\section{\module{datetime} ---
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Basic date and time types}
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\declaremodule{builtin}{datetime}
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\modulesynopsis{Basic date and time types.}
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\moduleauthor{Tim Peters}{tim@zope.com}
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\sectionauthor{Tim Peters}{tim@zope.com}
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\sectionauthor{A.M. Kuchling}{amk@amk.ca}
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\sectionauthor{Raymond D. Hettinger}{python@rcn.com}
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\versionadded{2.3}
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The \module{datetime} module supplies classes for manipulating dates
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and times in both simple and complex ways. While date and time
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arithmetic is supported, the focus of the implementation is on
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efficient field extraction, for output formatting and manipulation.
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There are two kinds of date and time objects: ``naive'' and ``aware''.
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This distinction refers to whether the object has any notion of time
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zone, daylight savings time, or other kind of algorithmic or political
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time adjustment. Whether a {naive} \class{datetime} object represents
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Coordinated Universal Time (UTC), local time, or time in some other
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timezone is purely up to the program, just like it's up to the program
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whether a particular number represents meters, miles, or mass. Naive
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\class{datetime} objects are easy to understand and to work with, at
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the cost of ignoring some aspects of reality.
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For applications requiring more, ``aware'' \class{datetime} subclasses add an
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optional time zone information object to the basic naive classes.
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These \class{tzinfo} objects capture information about the offset from
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UTC time, the time zone name, and whether Daylight Savings Time is in
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effect. Note that no concrete \class{tzinfo} classes are supplied by
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the \module{datetime} module. Instead, they provide a framework for
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incorporating the level of detail an app may require. The rules for
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time adjustment across the world are more political than rational, and
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there is no standard suitable for every app.
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The \module{datetime} module exports the following constants:
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\begin{datadesc}{MINYEAR}
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The smallest year number allowed in a \class{date},
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\class{datetime}, or \class{datetimetz} object. \constant{MINYEAR}
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is \code{1}.
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\end{datadesc}
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\begin{datadesc}{MAXYEAR}
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The largest year number allowed in a \class{date}, \class{datetime},
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or \class{datetimetz} object. \constant{MAXYEAR} is \code{9999}.
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\end{datadesc}
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\begin{seealso}
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\seemodule{calendar}{General calendar related functions.}
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\seemodule{time}{Time access and conversions.}
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\end{seealso}
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\subsection{Available Types}
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\begin{classdesc*}{date}
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An idealized naive date, assuming the current Gregorian calendar
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always was, and always will be, in effect.
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Attributes: \member{year}, \member{month}, and \member{day}.
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\end{classdesc*}
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\begin{classdesc*}{time}
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An idealized naive time, independent of any particular day, assuming
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that every day has exactly 24*60*60 seconds (there is no notion
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of "leap seconds" here).
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Attributes: \member{hour}, \member{minute}, \member{second}, and
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\member{microsecond}
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\end{classdesc*}
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\begin{classdesc*}{datetime}
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A combination of a naive date and a naive time.
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Attributes: \member{year}, \member{month}, \member{day},
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\member{hour}, \member{minute}, \member{second},
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and \member{microsecond}.
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\end{classdesc*}
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\begin{classdesc*}{timedelta}
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A duration, expressing the difference between two \class{date},
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\class{time}, or \class{datetime} instances, to microsecond
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resolution.
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\end{classdesc*}
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\begin{classdesc*}{tzinfo}
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An abstract base class for time zone information objects. These
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are used by the \class{datetimetz} and \class{timetz} classes to
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provided a customizable notion of time adjustment (for example, to
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account for time zone and/or daylight savings time).
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\end{classdesc*}
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\begin{classdesc*}{timetz}
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An aware subclass of \class{time}, supporting a customizable notion of
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time adjustment.
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\end{classdesc*}
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\begin{classdesc*}{datetimetz}
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An aware subclass of \class{datetime}, supporting a customizable notion of
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time adjustment.
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\end{classdesc*}
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Objects of these types are immutable.
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Objects of the \class{date}, \class{datetime}, and \class{time} types
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are always naive.
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An object \var{d} of type \class{timetz} or \class{datetimetz} may be
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naive or aware. \var{d} is aware if \code{\var{d}.tzinfo} is not
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\code{None}, and \code{\var{d}.tzinfo.utcoffset(\var{d})} does not return
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\code{None}. If \code{\var{d}.tzinfo} is \code{None}, or if
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\code{\var{d}.tzinfo} is not \code{None} but
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\code{\var{d}.tzinfo.utcoffset(\var{d})} returns \code{None}, \var{d}
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is naive.
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The distinction between naive and aware doesn't apply to
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\code{timedelta} objects.
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Subclass relationships:
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\begin{verbatim}
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object
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timedelta
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tzinfo
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time
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timetz
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date
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datetime
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datetimetz
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\end{verbatim}
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\subsection{\class{timedelta} Objects \label{datetime-timedelta}}
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A \class{timedelta} object represents a duration, the difference
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between two dates or times.
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\begin{classdesc}{timedelta}{days=0, seconds=0, microseconds=0,
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milliseconds=0, minutes=0, hours=0, weeks=0}
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All arguments are optional. Arguments may be ints, longs, or floats,
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and may be positive or negative.
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Only \var{days}, \var{seconds} and \var{microseconds} are stored
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internally. Arguments are converted to those units:
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\begin{verbatim}
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A millisecond is converted to 1000 microseconds.
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A minute is converted to 60 seconds.
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An hour is converted to 3600 seconds.
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A week is converted to 7 days.
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\end{verbatim}
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and days, seconds and microseconds are then normalized so that the
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representation is unique, with
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\begin{itemize}
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\item \code{0 <= \var{microseconds} < 1000000}
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\item \code{0 <= \var{seconds} < 3600*24} (the number of seconds in one day)
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\item \code{-999999999 <= \var{days} <= 999999999}
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\end{itemize}
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If any argument is a float, and there are fractional microseconds,
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the fractional microseconds left over from all arguments are combined
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and their sum is rounded to the nearest microsecond. If no
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argument is a float, the conversion and normalization processes
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are exact (no information is lost).
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If the normalized value of days lies outside the indicated range,
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\exception{OverflowError} is raised.
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Note that normalization of negative values may be surprising at first.
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For example,
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\begin{verbatim}
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>>> d = timedelta(microseconds=-1)
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>>> (d.days, d.seconds, d.microseconds)
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(-1, 86399, 999999)
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\end{verbatim}
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\end{classdesc}
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Class attributes are:
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\begin{memberdesc}{min}
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The most negative \class{timedelta} object,
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\code{timedelta(-999999999)}.
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\end{memberdesc}
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\begin{memberdesc}{max}
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The most positive \class{timedelta} object,
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\code{timedelta(days=999999999, hours=23, minutes=59, seconds=59,
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microseconds=999999)}.
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\end{memberdesc}
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\begin{memberdesc}{resolution}
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The smallest possible difference between non-equal
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\class{timedelta} objects, \code{timedelta(microseconds=1)}.
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\end{memberdesc}
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Note that, because of normalization, \code{timedelta.max} \textgreater
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\code{-timedelta.min}. \code{-timedelta.max} is not representable as
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a \class{timedelta} object.
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Instance attributes (read-only):
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\begin{tableii}{c|l}{code}{Attribute}{Value}
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\lineii{days}{Between -999999999 and 999999999 inclusive}
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\lineii{seconds}{Between 0 and 86399 inclusive}
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\lineii{microseconds}{Between 0 and 999999 inclusive}
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\end{tableii}
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Supported operations:
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\begin{tableiii}{c|l|c}{code}{Operation}{Result}{Notes}
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\lineiii{\var{t1} = \var{t2} + \var{t3}}
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{Sum of \var{t2} and \var{t3}.
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Afterwards \var{t1}-\var{t2} == \var{t3} and \var{t1}-\var{t3}
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== \var{t2} are true.}
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{(1)}
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\lineiii{\var{t1} = \var{t2} - \var{t3}}
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{Difference of \var{t2} and \var{t3}. Afterwards \var{t1} ==
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\var{t2} - \var{t3} and \var{t2} == \var{t1} + \var{t3} are
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true.}
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{(1)}
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\lineiii{\var{t1} = \var{t2} * \var{i} or \var{t1} = \var{i} * \var{t2}}
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{Delta multiplied by an integer or long.
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Afterwards \var{t1} // i == \var{t2} is true,
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provided \code{i != 0}.
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In general, \var{t1} * i == \var{t1} * (i-1) + \var{t1} is true.}
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{(1)}
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\lineiii{\var{t1} = \var{t2} // \var{i}}
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{The floor is computed and the remainder (if any) is thrown away.}
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{(2)}
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\lineiii{+\var{t1}}
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{Returns a \class{timedelta} object with the same value.}
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{}
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\lineiii{-\var{t1}}
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{equivalent to \class{timedelta}(-\var{t1.days}, -\var{t1.seconds},
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-\var{t1.microseconds}),and to \var{t1}* -1.}
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{(1)(3)}
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\lineiii{abs(\var{t})}
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{equivalent to +\var{t} when \code{t.days >= 0}, and to
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-\var{t} when \code{t.days < 0}.}
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{(1)}
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\end{tableiii}
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\noindent
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Notes:
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\begin{description}
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\item[(1)]
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This is exact, but may overflow.
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\item[(2)]
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Division by 0 raises \exception{ZeroDivisionError}.
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\item[(3)]
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-\var{timedelta.max} is not representable as a \class{timedelta} object.
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\end{description}
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In addition to the operations listed above \class{timedelta} objects
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support certain additions and subtractions with \class{date},
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\class{datetime}, and \class{datimetz} objects (see below).
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Comparisons of \class{timedelta} objects are supported with the
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\class{timedelta} object representing the smaller duration considered
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to be the smaller timedelta.
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\class{timedelta} objects are hashable (usable as dictionary key),
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support efficient pickling, and in Boolean contexts, a \class{timedelta}
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object is considered to be true if and only if it isn't equal to
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\code{timedelta(0)}.
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\subsection{\class{date} Objects \label{datetime-date}}
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A \class{date} object represents a date (year, month and day) in an idealized
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calendar, the current Gregorian calendar indefinitely extended in both
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directions. January 1 of year 1 is called day number 1, January 2 of year
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1 is called day number 2, and so on. This matches the definition of the
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"proleptic Gregorian" calendar in Dershowitz and Reingold's book
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\citetitle{Calendrical Calculations}, where it's the base calendar for all
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computations. See the book for algorithms for converting between
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proleptic Gregorian ordinals and many other calendar systems.
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\begin{classdesc}{date}{year, month, day}
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All arguments are required. Arguments may be ints or longs, in the
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following ranges:
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\begin{itemize}
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\item \code{MINYEAR <= \var{year} <= MAXYEAR}
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\item \code{1 <= \var{month} <= 12}
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\item \code{1 <= \var{day} <= number of days in the given month and year}
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\end{itemize}
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If an argument outside those ranges is given, \exception{ValueError}
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is raised.
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\end{classdesc}
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Other constructors, all class methods:
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\begin{methoddesc}{today}{}
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Return the current local date. This is equivalent to
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\code{date.fromtimestamp(time.time())}.
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\end{methoddesc}
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\begin{methoddesc}{fromtimestamp}{timestamp}
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Return the local date corresponding to the POSIX timestamp, such
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as is returned by \function{time.time()}. This may raise
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\exception{ValueError}, if the timestamp is out of the range of
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values supported by the platform C \cfunction{localtime()}
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function. It's common for this to be restricted to years from 1970
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through 2038.
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\end{methoddesc}
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\begin{methoddesc}{fromordinal}{ordinal}
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Return the date corresponding to the proleptic Gregorian ordinal,
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where January 1 of year 1 has ordinal 1. \exception{ValueError} is
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raised unless \code{1 <= \var{ordinal} <= date.max.toordinal()}.
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For any date \var{d}, \code{date.fromordinal(\var{d}.toordinal()) ==
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\var{d}}.
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\end{methoddesc}
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Class attributes:
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\begin{memberdesc}{min}
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The earliest representable date, \code{date(MINYEAR, 1, 1)}.
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\end{memberdesc}
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\begin{memberdesc}{max}
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The latest representable date, \code{date(MAXYEAR, 12, 31)}.
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\end{memberdesc}
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\begin{memberdesc}{resolution}
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The smallest possible difference between non-equal date
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objects, \code{timedelta(days=1)}.
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\end{memberdesc}
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Instance attributes (read-only):
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\begin{memberdesc}{year}
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Between \constant{MINYEAR} and \constant{MAXYEAR} inclusive
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\end{memberdesc}
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\begin{memberdesc}{month}
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Between 1 and 12 inclusive.
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\end{memberdesc}
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\begin{memberdesc}{day}
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Between 1 and the number of days in the given month of the given
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year.
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\end{memberdesc}
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Supported operations:
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\begin{itemize}
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\item
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date1 + timedelta -> date2
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timedelta + date1 -> date2
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date2 is timedelta.days days removed from the date1, moving forward
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in time if timedelta.days > 0, or backward if timedetla.days < 0.
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date2 - date1 == timedelta.days after. timedelta.seconds and
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timedelta.microseconds are ignored. \exception{OverflowError} is
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raised if date2.year would be smaller than \constant{MINYEAR} or
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larger than \constant{MAXYEAR}.
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\item
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date1 - timedelta -> date2
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Computes the date2 such that date2 + timedelta == date1. This
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isn't quite equivalent to date1 + (-timedelta), because -timedelta
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in isolation can overflow in cases where date1 - timedelta does
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not. timedelta.seconds and timedelta.microseconds are ignored.
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\item
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date1 - date2 -> timedelta
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This is exact, and cannot overflow. timedelta.seconds and
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timedelta.microseconds are 0, and date2 + timedelta == date1
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after.
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\item
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comparison of date to date, where date1 is considered less than
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date2 when date1 precedes date2 in time. In other words,
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date1 < date2 if and only if date1.toordinal() < date2.toordinal().
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\item
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hash, use as dict key
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\item
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efficient pickling
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\item
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in Boolean contexts, all \class{date} objects are considered to be true
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\end{itemize}
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Instance methods:
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\begin{methoddesc}{replace}{year, month, day}
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Return a date with the same value, except for those fields given
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new values by whichever keyword arguments are specified. For
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example, if \code{d == date(2002, 12, 31)}, then
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\code{d.replace(day=26) == date(2000, 12, 26)}.
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\end{methoddesc}
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\begin{methoddesc}{timetuple}{}
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Return a 9-element tuple of the form returned by
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\function{time.localtime()}. The hours, minutes and seconds are
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0, and the DST flag is -1.
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\code{\var{d}.timetuple()} is equivalent to
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\code{(\var{d}.year, \var{d}.month, \var{d}.day,
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0, 0, 0, \# h, m, s
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\var{d}.weekday(), \# 0 is Monday
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\var{d}.toordinal() - date(\var{d}.year, 1, 1).toordinal() + 1,
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\# day of year
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-1)}
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\end{methoddesc}
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\begin{methoddesc}{toordinal}{}
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Return the proleptic Gregorian ordinal of the date, where January 1
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of year 1 has ordinal 1. For any \class{date} object \var{d},
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\code{date.fromordinal(\var{d}.toordinal()) == \var{d}}.
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\end{methoddesc}
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\begin{methoddesc}{weekday}{}
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Return the day of the week as an integer, where Monday is 0 and
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Sunday is 6. For example, date(2002, 12, 4).weekday() == 2, a
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Wednesday.
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See also \method{isoweekday()}.
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\end{methoddesc}
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\begin{methoddesc}{isoweekday}{}
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Return the day of the week as an integer, where Monday is 1 and
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Sunday is 7. For example, date(2002, 12, 4).isoweekday() == 3, a
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Wednesday.
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See also \method{weekday()}, \method{isocalendar()}.
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\end{methoddesc}
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\begin{methoddesc}{isocalendar}{}
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Return a 3-tuple, (ISO year, ISO week number, ISO weekday).
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The ISO calendar is a widely used variant of the Gregorian calendar.
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See \url{http://www.phys.uu.nl/~vgent/calendar/isocalendar.htm}
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for a good explanation.
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The ISO year consists of 52 or 53 full weeks, and where a week starts
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on a Monday and ends on a Sunday. The first week of an ISO year is
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the first (Gregorian) calendar week of a year containing a Thursday.
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This is called week number 1, and the ISO year of that Thursday is
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the same as its Gregorian year.
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For example, 2004 begins on a Thursday, so the first week of ISO
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year 2004 begins on Monday, 29 Dec 2003 and ends on Sunday, 4 Jan
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2004, so that
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date(2003, 12, 29).isocalendar() == (2004, 1, 1)
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date(2004, 1, 4).isocalendar() == (2004, 1, 7)
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\end{methoddesc}
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\begin{methoddesc}{isoformat}{}
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Return a string representing the date in ISO 8601 format,
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'YYYY-MM-DD'. For example,
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date(2002, 12, 4).isoformat() == '2002-12-04'.
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\end{methoddesc}
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\begin{methoddesc}{__str__}{}
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For a date \var{d}, \code{str(\var{d})} is equivalent to
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\code{\var{d}.isoformat()}.
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\end{methoddesc}
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\begin{methoddesc}{ctime}{}
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Return a string representing the date, for example
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date(2002, 12, 4).ctime() == 'Wed Dec 4 00:00:00 2002'.
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\code{\var{d}.ctime()} is equivalent to
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\code{time.ctime(time.mktime(\var{d}.timetuple()))}
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|
on platforms where the native C \cfunction{ctime()} function
|
|
(which \function{time.ctime()} invokes, but which
|
|
\method{date.ctime()} does not invoke) conforms to the C standard.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{strftime}{format}
|
|
Return a string representing the date, controlled by an explicit
|
|
format string. Format codes referring to hours, minutes or seconds
|
|
will see 0 values.
|
|
See the section on \method{strftime()} behavior.
|
|
\end{methoddesc}
|
|
|
|
|
|
\subsection{\class{datetime} Objects \label{datetime-datetime}}
|
|
|
|
A \class{datetime} object is a single object containing all the
|
|
information from a \class{date} object and a time object. Like a
|
|
\class{date} object, \class{datetime} assumes the current Gregorian
|
|
calendar extended in both directions; like a time object,
|
|
\class{datetime} assumes there are exactly 3600*24 seconds in every
|
|
day.
|
|
|
|
\begin{classdesc}{datetime}{year, month, day,
|
|
hour=0, minute=0, second=0, microsecond=0}
|
|
The year, month and day arguments are required. Arguments may be
|
|
ints or longs, in the following ranges:
|
|
|
|
\begin{itemize}
|
|
\item \code{\member{MINYEAR} <= \var{year} <= \member{MAXYEAR}}
|
|
\item \code{1 <= \var{month} <= 12}
|
|
\item \code{1 <= \var{day} <= number of days in the given month and year}
|
|
\item \code{0 <= \var{hour} < 24}
|
|
\item \code{0 <= \var{minute} < 60}
|
|
\item \code{0 <= \var{second} < 60}
|
|
\item \code{0 <= \var{microsecond} < 1000000}
|
|
\end{itemize}
|
|
|
|
If an argument outside those ranges is given, \exception{ValueError}
|
|
is raised.
|
|
\end{classdesc}
|
|
|
|
Other constructors, all class methods:
|
|
|
|
\begin{methoddesc}{today}{}
|
|
Return the current local datetime. This is equivalent to
|
|
\code{datetime.fromtimestamp(time.time())}.
|
|
See also \method{now()}, \method{fromtimestamp()}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{now}{}
|
|
Return the current local datetime. This is like \method{today()},
|
|
but, if possible, supplies more precision than can be gotten from
|
|
going through a \function{time.time()} timestamp (for example,
|
|
this may be possible on platforms that supply the C
|
|
\cfunction{gettimeofday()} function).
|
|
See also \method{today()}, \method{utcnow()}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{utcnow}{}
|
|
Return the current UTC datetime. This is like \method{now()}, but
|
|
returns the current UTC date and time.
|
|
See also \method{now()}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{fromtimestamp}{timestamp}
|
|
Return the local \class{datetime} corresponding to the \POSIX{}
|
|
timestamp, such as is returned by \function{time.time()}. This
|
|
may raise \exception{ValueError}, if the timestamp is out of the
|
|
range of values supported by the platform C
|
|
\cfunction{localtime()} function. It's common for this to be
|
|
restricted to years in 1970 through 2038.
|
|
See also \method{utcfromtimestamp()}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{utcfromtimestamp}{timestamp}
|
|
Return the UTC \class{datetime} corresponding to the \POSIX{}
|
|
timestamp. This may raise \exception{ValueError}, if the
|
|
timestamp is out of the range of values supported by the platform
|
|
C \cfunction{gmtime()} function. It's common for this to be
|
|
restricted to years in 1970 through 2038.
|
|
See also \method{fromtimestamp()}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{fromordinal}{ordinal}
|
|
Return the \class{datetime} corresponding to the proleptic
|
|
Gregorian ordinal, where January 1 of year 1 has ordinal 1.
|
|
\exception{ValueError} is raised unless 1 <= ordinal <=
|
|
datetime.max.toordinal(). The hour, minute, second and
|
|
microsecond of the result are all 0.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{combine}{date, time}
|
|
Return a new \class{datetime} object whose date components are
|
|
equal to the given \class{date} object's, and whose time
|
|
components are equal to the given time object's. For any
|
|
\class{datetime} object \var{d}, \code{\var{d} ==
|
|
datetime.combine(\var{d}.date(), \var{d}.time())}. If date is a
|
|
\class{datetime} or \class{datetimetz} object, its time components
|
|
are ignored. If date is \class{datetimetz} object, its
|
|
\member{tzinfo} component is also ignored. If time is a
|
|
\class{timetz} object, its \member{tzinfo} component is ignored.
|
|
\end{methoddesc}
|
|
|
|
Class attributes:
|
|
|
|
\begin{memberdesc}{min}
|
|
The earliest representable \class{datetime},
|
|
\code{datetime(MINYEAR, 1, 1)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{max}
|
|
The latest representable \class{datetime},
|
|
\code{datetime(MAXYEAR, 12, 31, 23, 59, 59, 999999)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{resolution}
|
|
The smallest possible difference between non-equal \class{datetime}
|
|
objects, \code{timedelta(microseconds=1)}.
|
|
\end{memberdesc}
|
|
|
|
Instance attributes (read-only):
|
|
|
|
\begin{memberdesc}{year}
|
|
Between \constant{MINYEAR} and \constant{MAXYEAR} inclusive
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{month}
|
|
Between 1 and 12 inclusive
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{day}
|
|
Between 1 and the number of days in the given month of the given
|
|
year.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{hour}
|
|
In \code{range(24)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{minute}
|
|
In \code{range(60)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{second}
|
|
In \code{range(60)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{microsecond}
|
|
In \code{range(1000000)}.
|
|
\end{memberdesc}
|
|
|
|
Supported operations:
|
|
|
|
\begin{itemize}
|
|
\item
|
|
datetime1 + timedelta -> datetime2
|
|
timedelta + datetime1 -> datetime2
|
|
datetime2 is a duration of timedelta removed from datetime1, moving
|
|
forward in time if timedelta.days > 0, or backward if
|
|
timedelta.days < 0. datetime2 - datetime1 == timedelta after.
|
|
\exception{OverflowError} is raised if datetime2.year would be
|
|
smaller than \constant{MINYEAR} or larger than \constant{MAXYEAR}.
|
|
|
|
\item
|
|
datetime1 - timedelta -> datetime2
|
|
Computes the datetime2 such that datetime2 + timedelta == datetime1.
|
|
This isn't quite equivalent to datetime1 + (-timedelta), because
|
|
-timedelta in isolation can overflow in cases where
|
|
datetime1 - timedelta does not.
|
|
|
|
\item
|
|
datetime1 - datetime2 -> timedelta
|
|
This is exact, and cannot overflow.
|
|
datetime2 + timedelta == datetime1 after.
|
|
|
|
\item
|
|
comparison of \class{datetime} to datetime, where datetime1 is
|
|
considered less than datetime2 when datetime1 precedes datetime2
|
|
in time.
|
|
|
|
\item
|
|
hash, use as dict key
|
|
|
|
\item
|
|
efficient pickling
|
|
|
|
\item
|
|
in Boolean contexts, all \class{datetime} objects are considered
|
|
to be true
|
|
\end{itemize}
|
|
|
|
Instance methods:
|
|
|
|
\begin{methoddesc}{date}{}
|
|
Return \class{date} object with same year, month and day.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{time}{}
|
|
Return time object with same hour, minute, second and microsecond.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{replace}{year=, month=, day=, hour=, minute=,
|
|
second=, microsecond=}
|
|
Return a datetime with the same value, except for those fields given
|
|
new values by whichever keyword arguments are specified.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{astimezone}{tz}
|
|
Return a \class{datetimetz} with the same date and time fields, and
|
|
with \member{tzinfo} member \var{tz}. \var{tz} must be \code{None},
|
|
or an instance of a \class{tzinfo} subclass.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{timetuple}{}
|
|
Return a 9-element tuple of the form returned by
|
|
\function{time.localtime()}.
|
|
The DST flag is -1. \code{\var{d}.timetuple()} is equivalent to
|
|
\code{(\var{d}.year, \var{d}.month, \var{d}.day,
|
|
\var{d}.hour, \var{d}.minute, \var{d}.second,
|
|
\var{d}.weekday(), \# 0 is Monday
|
|
\var{d}.toordinal() - date(\var{d}.year, 1, 1).toordinal() + 1,
|
|
\# day of year
|
|
-1)}
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{toordinal}{}
|
|
Return the proleptic Gregorian ordinal of the date. The same as
|
|
\method{date.toordinal()}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{weekday}{}
|
|
Return the day of the week as an integer, where Monday is 0 and
|
|
Sunday is 6. The same as \method{date.weekday()}.
|
|
See also \method{isoweekday()}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{isoweekday}{}
|
|
Return the day of the week as an integer, where Monday is 1 and
|
|
Sunday is 7. The same as \method{date.isoweekday()}.
|
|
See also \method{weekday()}, \method{isocalendar()}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{isocalendar}{}
|
|
Return a 3-tuple, (ISO year, ISO week number, ISO weekday). The
|
|
same as \method{date.isocalendar()}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{isoformat}{sep='T'}
|
|
Return a string representing the date and time in ISO 8601 format,
|
|
YYYY-MM-DDTHH:MM:SS.mmmmmm
|
|
or, if self.microsecond is 0,
|
|
YYYY-MM-DDTHH:MM:SS
|
|
The optional argument \var{sep} (default \code{'T'}) is a
|
|
one-character separator, placed between the date and time portions
|
|
of the result. For example,
|
|
datetime(2002, 12, 4, 1, 2, 3, 4).isoformat(' ') ==
|
|
'2002-12-04 01:02:03.000004'
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{__str__}{}
|
|
For a \class{datetime} instance \var{d}, \code{str(\var{d})} is
|
|
equivalent to \code{\var{d}.isoformat(' ')}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{ctime}{}
|
|
Return a string representing the date, for example
|
|
datetime(2002, 12, 4, 20, 30, 40).ctime() == 'Wed Dec 4 20:30:40 2002'.
|
|
\code{d.ctime()} is equivalent to
|
|
\code{time.ctime(time.mktime(d.timetuple()))} on platforms where
|
|
the native C \cfunction{ctime()} function (which
|
|
\function{time.ctime()} invokes, but which
|
|
\method{datetime.ctime()} does not invoke) conforms to the C
|
|
standard.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{strftime}{format}
|
|
Return a string representing the date and time, controlled by an
|
|
explicit format string. See the section on \method{strftime()}
|
|
behavior.
|
|
\end{methoddesc}
|
|
|
|
|
|
\subsection{\class{time} Objects \label{datetime-time}}
|
|
|
|
A \class{time} object represents an idealized time of day, independent
|
|
of day and timezone.
|
|
|
|
\begin{classdesc}{time}{hour=0, minute=0, second=0, microsecond=0}
|
|
All arguments are optional. They may be ints or longs, in the
|
|
following ranges:
|
|
|
|
\begin{itemize}
|
|
\item \code{0 <= \var{hour} < 24}
|
|
\item \code{0 <= \var{minute} < 60}
|
|
\item \code{0 <= \var{second} < 60}
|
|
\item \code{0 <= \var{microsecond} < 1000000}
|
|
\end{itemize}
|
|
|
|
If an argument outside those ranges is given, \exception{ValueError}
|
|
is raised.
|
|
\end{classdesc}
|
|
|
|
Class attributes:
|
|
|
|
\begin{memberdesc}{min}
|
|
The earliest representable \class{time}, \code{time(0, 0, 0, 0)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{max}
|
|
The latest representable \class{time}, \code{time(23, 59, 59, 999999)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{resolution}
|
|
The smallest possible difference between non-equal \class{time}
|
|
objects, \code{timedelta(microseconds=1)}, although note that
|
|
arithmetic on \class{time} objects is not supported.
|
|
\end{memberdesc}
|
|
|
|
Instance attributes (read-only):
|
|
|
|
\begin{memberdesc}{hour}
|
|
In \code{range(24)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{minute}
|
|
In \code{range(60)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{second}
|
|
In \code{range(60)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{microsecond}
|
|
In \code{range(1000000)}.
|
|
\end{memberdesc}
|
|
|
|
Supported operations:
|
|
|
|
\begin{itemize}
|
|
\item
|
|
comparison of time to time, where time1 is considered
|
|
less than time2 when time1 precedes time2 in time.
|
|
|
|
\item
|
|
hash, use as dict key
|
|
|
|
\item
|
|
efficient pickling
|
|
|
|
\item
|
|
in Boolean contexts, a time object is considered to be true
|
|
if and only if it isn't equal to \code{time(0)}
|
|
\end{itemize}
|
|
|
|
Instance methods:
|
|
|
|
\begin{methoddesc}{replace}{hour=, minute=, second=, microsecond=}
|
|
Return a time with the same value, except for those fields given
|
|
new values by whichever keyword arguments are specified.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{isoformat}{}
|
|
Return a string representing the time in ISO 8601 format,
|
|
HH:MM:SS.mmmmmm
|
|
or, if self.microsecond is 0
|
|
HH:MM:SS
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{__str__}{}
|
|
For a time \var{t}, \code{str(\var{t})} is equivalent to
|
|
\code{\var{t}.isoformat()}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{strftime}{format}
|
|
Return a string representing the time, controlled by an explicit
|
|
format string. See the section on \method{strftime()} behavior.
|
|
\end{methoddesc}
|
|
|
|
|
|
\subsection{\class{tzinfo} Objects \label{datetime-tzinfo}}
|
|
|
|
\class{tzinfo} is an abstract base clase, meaning that this class
|
|
should not be instantiated directly. You need to derive a concrete
|
|
subclass, and (at least) supply implementations of the standard
|
|
\class{tzinfo} methods needed by the \class{datetime} methods you
|
|
use. The \module{datetime} module does not supply any concrete
|
|
subclasses of \class{tzinfo}.
|
|
|
|
An instance of (a concrete subclass of) \class{tzinfo} can be passed
|
|
to the constructors for \class{datetimetz} and \class{timetz} objects.
|
|
The latter objects view their fields as being in local time, and the
|
|
\class{tzinfo} object supports methods revealing offset of local time
|
|
from UTC, the name of the time zone, and DST offset, all relative to a
|
|
date or time object passed to them.
|
|
|
|
Special requirement for pickling: A \class{tzinfo} subclass must have an
|
|
\method{__init__} method that can be called with no arguments, else it
|
|
can be pickled but possibly not unpickled again. This is a technical
|
|
requirement that may be relaxed in the future.
|
|
|
|
A concrete subclass of \class{tzinfo} may need to implement the
|
|
following methods. Exactly which methods are needed depends on the
|
|
uses made of aware \module{datetime} objects. If in doubt, simply
|
|
implement all of them.
|
|
|
|
\begin{methoddesc}{utcoffset}{self, dt}
|
|
Return offset of local time from UTC, in minutes east of UTC. If
|
|
local time is west of UTC, this should be negative. Note that this
|
|
is intended to be the total offset from UTC; for example, if a
|
|
\class{tzinfo} object represents both time zone and DST adjustments,
|
|
\method{utcoffset()} should return their sum. If the UTC offset
|
|
isn't known, return \code{None}. Else the value returned must be
|
|
an integer, in the range -1439 to 1439 inclusive (1440 = 24*60;
|
|
the magnitude of the offset must be less than one day), or a
|
|
\class{timedelta} object representing a whole number of minutes
|
|
in the same range. Most implementations of \method{utcoffset()}
|
|
will probably look like:
|
|
|
|
\begin{verbatim}
|
|
return CONSTANT # fixed-offset class
|
|
return CONSTANT + self.dst(dt) # daylight-aware class
|
|
\end{verbatim}
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{tzname}{self, dt}
|
|
Return the timezone name corresponding to the \class{datetime} represented
|
|
by \var{dt}, as a string. Nothing about string names is defined by the
|
|
\module{datetime} module, and 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. Return
|
|
\code{None} if a string name isn't known. Note that this is a method
|
|
rather than a fixed string primarily because some \class{tzinfo} objects
|
|
will wish to return different names depending on the specific value
|
|
of \var{dt} passed, especially if the \class{tzinfo} class is
|
|
accounting for DST.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{dst}{self, dt}
|
|
Return the DST offset, in minutes east of UTC, or \code{None} if
|
|
DST information isn't known. Return \code{0} if DST is not in effect.
|
|
If DST is in effect, return the offset as an integer or
|
|
\class{timedelta} object (see \method{utcoffset()} for details).
|
|
Note that DST offset, if applicable, has
|
|
already been added to the UTC offset returned by
|
|
\method{utcoffset()}, so there's no need to consult \method{dst()}
|
|
unless you're interested in displaying DST info separately. For
|
|
example, \method{datetimetz.timetuple()} calls its \member{tzinfo}
|
|
member's \method{dst()} method to determine how the
|
|
\member{tm_isdst} flag should be set.
|
|
\end{methoddesc}
|
|
|
|
These methods are called by a \class{datetimetz} or \class{timetz} object,
|
|
in response to their methods of the same names. A \class{datetimetz}
|
|
object passes itself as the argument, and a \class{timetz} object passes
|
|
\code{None} as the argument. A \class{tzinfo} subclass's methods should
|
|
therefore be prepared to accept a \var{dt} argument of \code{None}, or of
|
|
class \class{datetimetz}.
|
|
|
|
When \code{None} is passed, it's up to the class designer to decide the
|
|
best response. For example, returning \code{None} is appropriate if the
|
|
class wishes to say that timetz objects don't participate in the
|
|
\class{tzinfo} protocol. In other applications, it may be more useful
|
|
for \code{utcoffset(None)} to return the standard UTC offset.
|
|
|
|
When a \class{datetimetz} object is passed in response to a
|
|
\class{datetimetz} method, \code{dt.tzinfo} is the same object as
|
|
\var{self}. \class{tzinfo} methods can rely on this, unless
|
|
user code calls \class{tzinfo} methods directly. The intent is that
|
|
the \class{tzinfo} methods interpret \var{dt} as being in local time,
|
|
and not need to worry about objects in other timezones.
|
|
|
|
Example \class{tzinfo} classes:
|
|
|
|
\verbatiminput{tzinfo-examples.py}
|
|
|
|
|
|
\subsection{\class{timetz} Objects \label{datetime-timetz}}
|
|
|
|
A time object represents a (local) time of day, independent of any
|
|
particular day, and subject to adjustment via a \class{tzinfo} object.
|
|
|
|
Constructor:
|
|
|
|
\begin{classdesc}{time}{hour=0, minute=0, second=0, microsecond=0,
|
|
tzinfo=None}
|
|
All arguments are optional. \var{tzinfo} may be \code{None}, or
|
|
an instance of a \class{tzinfo} subclass. The remaining arguments
|
|
may be ints or longs, in the following ranges:
|
|
|
|
\begin{itemize}
|
|
\item \code{0 <= \var{hour} < 24}
|
|
\item \code{0 <= \var{minute} < 60}
|
|
\item \code{0 <= \var{second} < 60}
|
|
\item \code{0 <= \var{microsecond} < 1000000}.
|
|
\end{itemize}
|
|
|
|
If an argument outside those ranges is given,
|
|
\exception{ValueError} is raised.
|
|
\end{classdesc}
|
|
|
|
Class attributes:
|
|
|
|
\begin{memberdesc}{min}
|
|
The earliest representable time, \code{timetz(0, 0, 0, 0)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{max}
|
|
The latest representable time, \code{timetz(23, 59, 59, 999999)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{resolution}
|
|
The smallest possible difference between non-equal \class{timetz}
|
|
objects, \code{timedelta(microseconds=1)}, although note that
|
|
arithmetic on \class{timetz} objects is not supported.
|
|
\end{memberdesc}
|
|
|
|
Instance attributes (read-only):
|
|
|
|
\begin{memberdesc}{hour}
|
|
In \code{range(24)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{minute}
|
|
In \code{range(60)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{second}
|
|
In \code{range(60)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{microsecond}
|
|
In \code{range(1000000)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{tzinfo}
|
|
The object passed as the tzinfo argument to the \class{timetz}
|
|
constructor, or \code{None} if none was passed.
|
|
\end{memberdesc}
|
|
|
|
Supported operations:
|
|
|
|
\begin{itemize}
|
|
\item
|
|
comparison of \class{timetz} to \class{time} or \class{timetz},
|
|
where \var{a} is considered less than \var{b} when \var{a} precedes
|
|
\var{b} in time. If one comparand is naive and the other is aware,
|
|
\exception{TypeError} is raised. If both comparands are aware, and
|
|
have the same \member{tzinfo} member, the common \member{tzinfo}
|
|
member is ignored and the base times are compared. If both
|
|
comparands are aware and have different \member{tzinfo} members,
|
|
the comparands are first adjusted by subtracting their UTC offsets
|
|
(obtained from \code{self.utcoffset()}).
|
|
|
|
\item
|
|
hash, use as dict key
|
|
|
|
\item
|
|
pickling
|
|
|
|
\item
|
|
in Boolean contexts, a \class{timetz} object is considered to be
|
|
true if and only if, after converting it to minutes and
|
|
subtracting \method{utcoffset()} (or \code{0} if that's
|
|
\code{None}), the result is non-zero.
|
|
\end{itemize}
|
|
|
|
Instance methods:
|
|
|
|
\begin{methoddesc}{replace}(hour=, minute=, second=, microsecond=, tzinfo=)
|
|
Return a \class{timetz} with the same value, except for those fields given
|
|
new values by whichever keyword arguments are specified. Note that
|
|
\code{tzinfo=None} can be specified to create a naive \class{timetz} from an
|
|
aware \class{timetz}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{isoformat}{}
|
|
Return a string representing the time in ISO 8601 format,
|
|
HH:MM:SS.mmmmmm
|
|
or, if self.microsecond is 0,
|
|
HH:MM:SS
|
|
If \method{utcoffset()} does not return \code{None}, a 6-character
|
|
string is appended, giving the UTC offset in (signed) hours and
|
|
minutes:
|
|
HH:MM:SS.mmmmmm+HH:MM
|
|
or, if self.microsecond is 0,
|
|
HH:MM:SS+HH:MM
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{__str__}{}
|
|
For a \class{timetz} \var{t}, \code{str(\var{t})} is equivalent to
|
|
\code{\var{t}.isoformat()}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{strftime}{format}
|
|
Return a string representing the time, controlled by an explicit
|
|
format string. See the section on \method{strftime()} behavior.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{utcoffset}{}
|
|
If \member{tzinfo} is \code{None}, returns \code{None}, else
|
|
\code{tzinfo.utcoffset(self)} converted to a \class{timedelta}
|
|
object.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{tzname}{}
|
|
If \member{tzinfo} is \code{None}, returns \code{None}, else
|
|
\code{tzinfo.tzname(self)}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{dst}{}
|
|
If \member{tzinfo} is \code{None}, returns \code{None}, else
|
|
\code{tzinfo.dst(self)} converted to a \class{timedelta} object.
|
|
\end{methoddesc}
|
|
|
|
|
|
|
|
\subsection{ \class{datetimetz} Objects \label{datetime-datetimetz}}
|
|
|
|
\begin{notice}[warning]
|
|
I think this is \emph{still} missing some methods from the
|
|
Python implementation.
|
|
\end{notice}
|
|
|
|
A \class{datetimetz} object is a single object containing all the information
|
|
from a \class{date} object and a \class{timetz} object.
|
|
|
|
Constructor:
|
|
|
|
\begin{classdesc}{datetimetz}{year, month, day,
|
|
hour=0, minute=0, second=0, microsecond=0,
|
|
tzinfo=None}
|
|
The year, month and day arguments are required. \var{tzinfo} may
|
|
be \code{None}, or an instance of a \class{tzinfo} subclass. The
|
|
remaining arguments may be ints or longs, in the following ranges:
|
|
|
|
\begin{itemize}
|
|
\item \code{MINYEAR <= \var{year} <= MAXYEAR}
|
|
\item \code{1 <= \var{month} <= 12}
|
|
\item \code{1 <= \var{day} <= number of days in the given month and year}
|
|
\item \code{0 <= \var{hour} < 24}
|
|
\item \code{0 <= \var{minute} < 60}
|
|
\item \code{0 <= \var{second} < 60}
|
|
\item \code{0 <= \var{microsecond} < 1000000}
|
|
\end{itemize}
|
|
|
|
If an argument outside those ranges is given,
|
|
\exception{ValueError} is raised.
|
|
\end{classdesc}
|
|
|
|
Other constructors (class methods):
|
|
|
|
\begin{funcdesc}{today}{}
|
|
\methodline{utcnow}{}
|
|
\methodline{utcfromtimestamp}{timestamp}
|
|
\methodline{fromordinal}{ordinal}
|
|
These are the same as the \class{datetime} class methods of the
|
|
same names, except that they construct a \class{datetimetz}
|
|
object, with tzinfo \code{None}.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{now}{\optional{tzinfo=None}}
|
|
\methodline{fromtimestamp}{timestamp\optional{, tzinfo=None}}
|
|
These are the same as the \class{datetime} class methods of the
|
|
same names, except that they accept an additional, optional tzinfo
|
|
argument, and construct a \class{datetimetz} object with that
|
|
\class{tzinfo} object attached.
|
|
\end{funcdesc}
|
|
|
|
\begin{funcdesc}{combine}{date, time}
|
|
This is the same as \method{datetime.combine()}, except that it
|
|
constructs a \class{datetimetz} object, and, if the time object is
|
|
of type timetz, the \class{datetimetz} object has the same
|
|
\class{tzinfo} object as the time object.
|
|
\end{funcdesc}
|
|
|
|
Class attributes:
|
|
|
|
\begin{memberdesc}{min}
|
|
The earliest representable \class{datetimetz},
|
|
\code{datetimetz(MINYEAR, 1, 1)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{max}
|
|
The latest representable \class{datetime},
|
|
\code{datetimetz(MAXYEAR, 12, 31, 23, 59, 59, 999999)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{resolution}
|
|
The smallest possible difference between non-equal \class{datetimetz}
|
|
objects, \code{timedelta(microseconds=1)}.
|
|
\end{memberdesc}
|
|
|
|
Instance attributes, all read-only:
|
|
|
|
\begin{memberdesc}{year}
|
|
Between \constant{MINYEAR} and \constant{MAXYEAR}, inclusive.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{month}
|
|
Between 1 and 12 inclusive
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{day}
|
|
Between 1 and the number of days in the given month of the given
|
|
year.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{hour}
|
|
In \code{range(24)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{minute}
|
|
In \code{range(60)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{second}
|
|
In \code{range(60)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{microsecond}
|
|
In \code{range(1000000)}.
|
|
\end{memberdesc}
|
|
|
|
\begin{memberdesc}{tzinfo}
|
|
The object passed as the \var{tzinfo} argument to the
|
|
\class{datetimetz} constructor, or \code{None} if none was passed.
|
|
\end{memberdesc}
|
|
|
|
Supported operations:
|
|
|
|
\begin{itemize}
|
|
\item
|
|
datetimetz1 + timedelta -> datetimetz2
|
|
timedelta + datetimetz1 -> datetimetz2
|
|
|
|
The same as addition of \class{datetime} objects, except that
|
|
datetimetz2.tzinfo is set to datetimetz1.tzinfo.
|
|
|
|
\item
|
|
datetimetz1 - timedelta -> datetimetz2
|
|
|
|
The same as addition of \class{datetime} objects, except that
|
|
datetimetz2.tzinfo is set to datetimetz1.tzinfo.
|
|
|
|
\item
|
|
aware_datetimetz1 - aware_datetimetz2 -> timedelta
|
|
naive_datetimetz1 - naive_datetimetz2 -> timedelta
|
|
naive_datetimetz1 - datetime2 -> timedelta
|
|
datetime1 - naive_datetimetz2 -> timedelta
|
|
|
|
Subtraction of a \class{datetime} or \class{datetimetz}, from a
|
|
\class{datetime} or \class{datetimetz}, is defined only if both
|
|
operands are naive, or if both are aware. If one is aware and the
|
|
other is naive, \exception{TypeError} is raised.
|
|
|
|
If both are naive, or both are aware and have the same \member{tzinfo}
|
|
member, subtraction acts as for \class{datetime} subtraction.
|
|
|
|
If both are aware and have different \member{tzinfo} members,
|
|
\code{a-b} acts as if \var{a} and \var{b} were first converted to UTC
|
|
datetimes (by subtracting \code{a.utcoffset()} minutes from \var{a},
|
|
and \code{b.utcoffset()} minutes from \var{b}), and then doing
|
|
\class{datetime} subtraction, except that the implementation never
|
|
overflows.
|
|
|
|
\item
|
|
comparison of \class{datetimetz} to \class{datetime} or
|
|
\class{datetimetz}, where \var{a} is considered less than \var{b}
|
|
when \var{a} precedes \var{b} in time. If one comparand is naive and
|
|
the other is aware, \exception{TypeError} is raised. If both
|
|
comparands are aware, and have the same \member{tzinfo} member,
|
|
the common \member{tzinfo} member is ignored and the base datetimes
|
|
are compared. If both comparands are aware and have different
|
|
\member{tzinfo} members, the comparands are first adjusted by
|
|
subtracting their UTC offsets (obtained from \code{self.utcoffset()}).
|
|
|
|
\item
|
|
hash, use as dict key
|
|
|
|
\item
|
|
efficient pickling
|
|
|
|
\item
|
|
in Boolean contexts, all \class{datetimetz} objects are considered to be
|
|
true
|
|
\end{itemize}
|
|
|
|
Instance methods:
|
|
|
|
\begin{methoddesc}{date}{}
|
|
\methodline{time}{}
|
|
\methodline{toordinal}{}
|
|
\methodline{weekday}{}
|
|
\methodline{isoweekday}{}
|
|
\methodline{isocalendar}{}
|
|
\methodline{ctime}{}
|
|
\methodline{__str__}{}
|
|
\methodline{strftime}{format}
|
|
These are the same as the \class{datetime} methods of the same names.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{timetz}{}
|
|
Return \class{timetz} object with same hour, minute, second, microsecond,
|
|
and tzinfo.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{replace}{year=, month=, day=, hour=, minute=, second=,
|
|
microsecond=, tzinfo=}
|
|
Return a datetimetz with the same value, except for those fields given
|
|
new values by whichever keyword arguments are specified. Note that
|
|
\code{tzinfo=None} can be specified to create a naive datetimetz from
|
|
an aware datetimetz.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{astimezone}{tz}
|
|
Return a \class{datetimetz} with new tzinfo member \var{tz}. \var{tz}
|
|
must be \code{None}, or an instance of a \class{tzinfo} subclass. If
|
|
\var{tz} is \code{None}, self is naive, or
|
|
\code{tz.utcoffset(self)} returns \code{None},
|
|
\code{self.astimezone(tz)} is equivalent to
|
|
\code{self.replace(tzinfo=tz)}: a new timezone object is attached
|
|
without any conversion of date or time fields. If self is aware and
|
|
\code{tz.utcoffset(self)} does not return \code{None}, the date and
|
|
time fields are adjusted so that the result is local time in timezone
|
|
tz, representing the same UTC time as self.
|
|
XXX [The treatment of endcases remains unclear: for DST-aware
|
|
classes, one hour per year has two spellings in local time, and
|
|
another hour has no spelling in local time.] XXX
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{utcoffset}{}
|
|
If \member{tzinfo} is \code{None}, returns \code{None}, else
|
|
\code{tzinfo.utcoffset(self)} converted to a \class{timedelta}
|
|
object.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{tzname}{}
|
|
If \member{tzinfo} is \code{None}, returns \code{None}, else
|
|
returns \code{tzinfo.tzname(self)}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{dst}{}
|
|
If \member{tzinfo} is \code{None}, returns \code{None}, else
|
|
\code{tzinfo.dst(self)} converted to a \class{timedelta}
|
|
object.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{timetuple}{}
|
|
Like \function{datetime.timetuple()}, but sets the
|
|
\member{tm_isdst} flag according to the \method{dst()} method: if
|
|
\method{dst()} returns \code{None}, \member{tm_isdst} is set to
|
|
\code{-1}; else if \method{dst()} returns a non-zero value,
|
|
\member{tm_isdst} is set to \code{1}; else \code{tm_isdst} is set
|
|
to \code{0}.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{utctimetuple}{}
|
|
If \class{datetimetz} instance \var{d} is naive, this is the same as
|
|
\code{\var{d}.timetuple()} except that \member{tm_isdst} is forced to 0
|
|
regardless of what \code{d.dst()} returns. DST is never in effect
|
|
for a UTC time.
|
|
|
|
If \var{d} is aware, \var{d} is normalized to UTC time, by subtracting
|
|
\code{\var{d}.utcoffset()} minutes, and a timetuple for the
|
|
normalized time is returned. \member{tm_isdst} is forced to 0.
|
|
Note that the result's \member{tm_year} field may be
|
|
\constant{MINYEAR}-1 or \constant{MAXYEAR}+1, if \var{d}.year was
|
|
\code{MINYEAR} or \code{MAXYEAR} and UTC adjustment spills over a
|
|
year boundary.
|
|
\end{methoddesc}
|
|
|
|
\begin{methoddesc}{isoformat}{sep='T'}
|
|
Return a string representing the date and time in ISO 8601 format,
|
|
YYYY-MM-DDTHH:MM:SS.mmmmmm
|
|
or, if \member{microsecond} is 0,
|
|
YYYY-MM-DDTHH:MM:SS
|
|
|
|
If \method{utcoffset()} does not return \code{None}, a 6-character
|
|
string is appended, giving the UTC offset in (signed) hours and
|
|
minutes:
|
|
YYYY-MM-DDTHH:MM:SS.mmmmmm+HH:MM
|
|
or, if \member{microsecond} is 0
|
|
YYYY-MM-DDTHH:MM:SS+HH:MM
|
|
|
|
The optional argument \var{sep} (default \code{'T'}) is a
|
|
one-character separator, placed between the date and time portions
|
|
of the result. For example,
|
|
|
|
\begin{verbatim}
|
|
>>> from datetime import *
|
|
>>> class TZ(tzinfo):
|
|
... def utcoffset(self, dt): return -399
|
|
...
|
|
>>> datetimetz(2002, 12, 25, tzinfo=TZ()).isoformat(' ')
|
|
'2002-12-25 00:00:00-06:39'
|
|
\end{verbatim}
|
|
\end{methoddesc}
|
|
|
|
\code{str(\var{d})} is equivalent to \code{\var{d}.isoformat(' ')}.
|
|
|
|
|
|
\subsection{\method{strftime()} Behavior}
|
|
|
|
\class{date}, \class{datetime}, \class{datetimetz}, \class{time},
|
|
and \class{timetz} objects all support a \code{strftime(\var{format})}
|
|
method, to create a string representing the time under the control of
|
|
an explicit format string. Broadly speaking,
|
|
\code{d.strftime(fmt)}
|
|
acts like the \refmodule{time} module's
|
|
\code{time.strftime(fmt, d.timetuple())}
|
|
although not all objects support a \method{timetuple()} method.
|
|
|
|
For \class{time} and \class{timetz} objects, the format codes for
|
|
year, month, and day should not be used, as time objects have no such
|
|
values. If they're used anyway, \code{1900} is substituted for the
|
|
year, and \code{0} for the month and day.
|
|
|
|
For \class{date} objects, the format codes for hours, minutes, and
|
|
seconds should not be used, as \class{date} objects have no such
|
|
values. If they're used anyway, \code{0} is substituted for them.
|
|
|
|
For a naive object, the \code{\%z} and \code{\%Z} format codes are
|
|
replaced by empty strings.
|
|
|
|
For an aware object:
|
|
|
|
\begin{itemize}
|
|
\item[\code{\%z}]
|
|
\method{utcoffset()} is transformed into a 5-character string of
|
|
the form +HHMM or -HHMM, where HH is a 2-digit string giving the
|
|
number of UTC offset hours, and MM is a 2-digit string giving the
|
|
number of UTC offset minutes. For example, if
|
|
\method{utcoffset()} returns \code{timedelta(hours=-3, minutes=-30)},
|
|
\code{\%z} is replaced with the string \code{'-0330'}.
|
|
|
|
\item[\code{\%Z}]
|
|
If \method{tzname()} returns \code{None}, \code{\%Z} is replaced
|
|
by an empty string. Otherwise \code{\%Z} is replaced by the returned
|
|
value, which must be a string.
|
|
\end{itemize}
|
|
|
|
The full set of format codes supported varies across platforms,
|
|
because Python calls the platform C library's \function{strftime()}
|
|
function, and platform variations are common. The documentation for
|
|
Python's \refmodule{time} module lists the format codes that the C
|
|
standard (1989 version) requires, and those work on all platforms
|
|
with a standard C implementation. Note that the 1999 version of the
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C standard added additional format codes.
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The exact range of years for which \method{strftime()} works also
|
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varies across platforms. Regardless of platform, years before 1900
|
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cannot be used.
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\begin{comment}
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\subsection{C API}
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Struct typedefs:
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PyDateTime_Date
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PyDateTime_DateTime
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PyDateTime_DateTimeTZ
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PyDateTime_Time
|
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PyDateTime_TimeTZ
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|
PyDateTime_Delta
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|
PyDateTime_TZInfo
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|
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|
Type-check macros:
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PyDate_Check(op)
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PyDate_CheckExact(op)
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|
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PyDateTime_Check(op)
|
|
PyDateTime_CheckExact(op)
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|
|
|
PyDateTimeTZ_Check(op)
|
|
PyDateTimeTZ_CheckExact(op)
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|
|
|
PyTime_Check(op)
|
|
PyTime_CheckExact(op)
|
|
|
|
PyTimeTZ_Check(op)
|
|
PyTimeTZ_CheckExact(op)
|
|
|
|
PyDelta_Check(op)
|
|
PyDelta_CheckExact(op)
|
|
|
|
PyTZInfo_Check(op)
|
|
PyTZInfo_CheckExact(op)
|
|
|
|
Accessor macros:
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|
|
|
All objects are immutable, so accessors are read-only. All macros
|
|
return ints:
|
|
|
|
For \class{date}, \class{datetime}, and \class{datetimetz} instances:
|
|
PyDateTime_GET_YEAR(o)
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|
PyDateTime_GET_MONTH(o)
|
|
PyDateTime_GET_DAY(o)
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|
|
|
For \class{datetime} and \class{datetimetz} instances:
|
|
PyDateTime_DATE_GET_HOUR(o)
|
|
PyDateTime_DATE_GET_MINUTE(o)
|
|
PyDateTime_DATE_GET_SECOND(o)
|
|
PyDateTime_DATE_GET_MICROSECOND(o)
|
|
|
|
For \class{time} and \class{timetz} instances:
|
|
PyDateTime_TIME_GET_HOUR(o)
|
|
PyDateTime_TIME_GET_MINUTE(o)
|
|
PyDateTime_TIME_GET_SECOND(o)
|
|
PyDateTime_TIME_GET_MICROSECOND(o)
|
|
|
|
\end{comment}
|