diff options
Diffstat (limited to 'Doc')
| -rw-r--r-- | Doc/lib/libstdtypes.tex | 34 |
1 files changed, 19 insertions, 15 deletions
diff --git a/Doc/lib/libstdtypes.tex b/Doc/lib/libstdtypes.tex index 2ba87c4..2bd6420 100644 --- a/Doc/lib/libstdtypes.tex +++ b/Doc/lib/libstdtypes.tex @@ -161,7 +161,7 @@ only by sequence types (below). \subsection{Numeric Types \label{typesnumeric}} -There are four numeric types: \dfn{plain integers}, \dfn{long integers}, +There are four numeric types: \dfn{plain integers}, \dfn{long integers}, \dfn{floating point numbers}, and \dfn{complex numbers}. Plain integers (also just called \dfn{integers}) are implemented using \ctype{long} in C, which gives them at least 32 @@ -178,7 +178,7 @@ working with. Complex numbers have a real and imaginary part, which are both implemented using \ctype{double} in C. To extract these parts from -a complex number \var{z}, use \code{\var{z}.real} and \code{\var{z}.imag}. +a complex number \var{z}, use \code{\var{z}.real} and \code{\var{z}.imag}. Numbers are created by numeric literals or as the result of built-in functions and operators. Unadorned integer literals (including hex @@ -248,7 +248,7 @@ Notes: \item[(1)] For (plain or long) integer division, the result is an integer. -The result is always rounded towards minus infinity: 1/2 is 0, +The result is always rounded towards minus infinity: 1/2 is 0, (-1)/2 is -1, 1/(-2) is -1, and (-1)/(-2) is 0. Note that the result is a long integer if either operand is a long integer, regardless of the numeric value. @@ -472,7 +472,7 @@ Notes: the end of the string: \code{len(\var{s}) + \var{i}} or \code{len(\var{s}) + \var{j}} is substituted. But note that \code{-0} is still \code{0}. - + \item[(3)] The slice of \var{s} from \var{i} to \var{j} is defined as the sequence of items with index \var{k} such that \code{\var{i} <= \var{k} < \var{j}}. If \var{i} or \var{j} is greater than @@ -808,7 +808,7 @@ are replaced by \code{\%g} conversions.\footnote{ Additional string operations are defined in standard modules \refmodule{string}\refstmodindex{string} and -\refmodule{re}.\refstmodindex{re} +\refmodule{re}.\refstmodindex{re} \subsubsection{XRange Type \label{typesseq-xrange}} @@ -881,7 +881,7 @@ Notes: no longer works in Python 2.0. Use of this misfeature has been deprecated since Python 1.4. -\item[(2)] Raises an exception when \var{x} is not a list object. The +\item[(2)] Raises an exception when \var{x} is not a list object. The \method{extend()} method is experimental and not supported by mutable sequence types other than lists. @@ -1034,7 +1034,7 @@ over a dictionary, as often used in set algorithms. File objects\obindex{file} are implemented using C's \code{stdio} package and can be created with the built-in constructor -\function{file()}\bifuncindex{file} described in section +\function{file()}\bifuncindex{file} described in section \ref{built-in-funcs}, ``Built-in Functions.''\footnote{\function{file()} is new in Python 2.2. The older built-in \function{open()} is an alias for \function{file()}.} @@ -1100,10 +1100,10 @@ Files have the following methods: \begin{methoddesc}[file]{readline}{\optional{size}} Read one entire line from the file. A trailing newline character is kept in the string\footnote{ - The advantage of leaving the newline on is that an empty string - can be returned to mean \EOF{} without being ambiguous. Another - advantage is that (in cases where it might matter, for example. if you - want to make an exact copy of a file while scanning its lines) + The advantage of leaving the newline on is that an empty string + can be returned to mean \EOF{} without being ambiguous. Another + advantage is that (in cases where it might matter, for example. if you + want to make an exact copy of a file while scanning its lines) you can tell whether the last line of a file ended in a newline or not (yes this happens!). } (but may be absent when a file ends with an @@ -1152,11 +1152,15 @@ Files have the following methods: \end{methoddesc} \begin{methoddesc}[file]{truncate}{\optional{size}} - Truncate the file's size. If the optional \var{size} argument + Truncate the file's size. If the optional \var{size} argument is present, the file is truncated to (at most) that size. The size - defaults to the current position. Availability of this function - depends on the operating system version (for example, not all - \UNIX{} versions support this operation). + defaults to the current position. The current file position is + not changed. Note that if a specified size exceeds the file's + current size, the result is platform-dependent: possibilities + include that file may remain unchanged, increase to the specified + size as if zero-filled, or increase to the specified size with + undefined new content. + Availability: Windows, many \UNIX variants. \end{methoddesc} \begin{methoddesc}[file]{write}{str} |