Mercurial > cpython-lru_cache-weakref
diff Doc/lib/libstdtypes.tex @ 24599:d7ca0a2ce074 legacy-trunk
Document file.next(). Mark xreadlines obsolete (both method and
module). (One thing remains to be done: the gzip class has an
xreadline method; this ought to be replaced by an iterator as well.)
| author | Guido van Rossum <guido@python.org> |
|---|---|
| date | Tue, 06 Aug 2002 17:01:28 +0000 |
| parents | 12e146171f3d |
| children | 110c6edaf62f |
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--- a/Doc/lib/libstdtypes.tex Tue Aug 06 16:58:21 2002 +0000 +++ b/Doc/lib/libstdtypes.tex Tue Aug 06 17:01:28 2002 +0000 @@ -1122,12 +1122,6 @@ objects. \end{methoddesc} -\begin{methoddesc}[file]{isatty}{} - Return \code{True} if the file is connected to a tty(-like) device, else - \code{False}. \note{If a file-like object is not associated - with a real file, this method should \emph{not} be implemented.} -\end{methoddesc} - \begin{methoddesc}[file]{fileno}{} \index{file descriptor} \index{descriptor, file} @@ -1141,6 +1135,29 @@ this method!} \end{methoddesc} +\begin{methoddesc}[file]{isatty}{} + Return \code{True} if the file is connected to a tty(-like) device, else + \code{False}. \note{If a file-like object is not associated + with a real file, this method should \emph{not} be implemented.} +\end{methoddesc} + +\begin{methoddesc}[file]{next}{} +A file object is its own iterator, i.e. \code{iter(\var{f})} returns +\var{f} (unless \var{f} is closed). When a file is used as an +iterator, typically in a \keyword{for} loop (for example, +\code{for line in f: print line}), the \method{next()} method is +called repeatedly. This method returns the next input line, or raises +\exception{StopIteration} when \EOF{} is hit. In order to make a +\keyword{for} loop the most efficient way of looping over the lines of +a file (a very common operation), the \method{next()} method uses a +hidden read-ahead buffer. As a consequence of using a read-ahead +buffer, combining \method{next()} with other file methods (like +\method{readline()}) does not work right. However, using +\method{seek()} to reposition the file to an absolute position will +flush the read-ahead buffer. +\versionadded{2.3} +\end{methoddesc} + \begin{methoddesc}[file]{read}{\optional{size}} Read at most \var{size} bytes from the file (less if the read hits \EOF{} before obtaining \var{size} bytes). If the \var{size} @@ -1184,10 +1201,9 @@ \end{methoddesc} \begin{methoddesc}[file]{xreadlines}{} - Equivalent to - \function{xreadlines.xreadlines(\var{file})}.\refstmodindex{xreadlines} - (See the \refmodule{xreadlines} module for more information.) + This method returns the same thing as \code{iter(f)}. \versionadded{2.1} + \deprecated{2.3}{Use \code{for line in file} instead.} \end{methoddesc} \begin{methoddesc}[file]{seek}{offset\optional{, whence}}
