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author | Tim Peters <tim.peters@gmail.com> | 2002-12-23 22:21:52 (GMT) |
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committer | Tim Peters <tim.peters@gmail.com> | 2002-12-23 22:21:52 (GMT) |
commit | 29fb9c7e076232096fe2c81647592660ca498228 (patch) | |
tree | 674c7de732bacae52c4de7d37666878b65ff3aaa /Doc/lib/libdatetime.tex | |
parent | 0a116f3a2901b040faa356ffc3dbb91a7f00d215 (diff) | |
download | cpython-29fb9c7e076232096fe2c81647592660ca498228.zip cpython-29fb9c7e076232096fe2c81647592660ca498228.tar.gz cpython-29fb9c7e076232096fe2c81647592660ca498228.tar.bz2 |
Brought the strftime explanation into synch with the plain-text sandbox
docs, and moved its section to the end (before the "C API" section,
which latter doesn't really belong in the Library manual).
Diffstat (limited to 'Doc/lib/libdatetime.tex')
-rw-r--r-- | Doc/lib/libdatetime.tex | 101 |
1 files changed, 56 insertions, 45 deletions
diff --git a/Doc/lib/libdatetime.tex b/Doc/lib/libdatetime.tex index 4435ae3..a7d9926 100644 --- a/Doc/lib/libdatetime.tex +++ b/Doc/lib/libdatetime.tex @@ -123,51 +123,6 @@ object datetimetz \end{verbatim} - -\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, -\begin{verbatim} -d.strftime(fmt) -\end{verbatim} -acts like the \refmodule{time} module's -\begin{verbatim} -time.strftime(fmt, d.timetuple()) -\end{verbatim} -although not all objects support a \method{timetuple()} method. - -For time and \class{timetz} objects, format codes for year, month, and -day should not be used, as time objects have no such values. \code{0} -is used instead. - -For date objects, format codes for hours, minutes, and seconds should -not be used, as date objects have no such values. \code{0} is used -instead. - -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 -180, \code{\%z} is replaced with the - string \code{'-0300'}. - - \item[\code{\%Z}] - If \method{tzname()} returns \code{None}, \code{\%Z} is replaced - by an empty string. Else \code{\%Z} is replaced by the returned - value, which must be a string. -\end{itemize} - - \subsection{\class{timedelta} \label{datetime-timedelta}} A \class{timedelta} object represents a duration, the difference @@ -1156,6 +1111,62 @@ Instance methods: \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, +\begin{verbatim} +d.strftime(fmt) +\end{verbatim} +acts like the \refmodule{time} module's +\begin{verbatim} +time.strftime(fmt, d.timetuple()) +\end{verbatim} +although not all objects support a \method{timetuple()} method. + +For \class{time} and \class{timetz} objects, format codes for year, +month, and day should not be used, as time objects have no such values. +\code{1900} is used for the year, and \code{0} for the month and day. + +For \class{date} objects, format codes for hours, minutes, and seconds +should not be used, as date objects have no such values. \code{0} is +used instead. + +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 -180, \code{\%z} is replaced with the + string \code{'-0300'}. + + \item[\code{\%Z}] + If \method{tzname()} returns \code{None}, \code{\%Z} is replaced + by an empty string. Else \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 +C standard added additional format codes. + +The exact range of years for which \method{strftime()} works also +varies across platforms. Regardless of platform, years before 1900 +cannot be used. + + \subsection{C API} Struct typedefs: |