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Diffstat (limited to 'Doc/lib/libre.tex')
| -rw-r--r-- | Doc/lib/libre.tex | 72 |
1 files changed, 43 insertions, 29 deletions
diff --git a/Doc/lib/libre.tex b/Doc/lib/libre.tex index 8e273bce7f..8397461797 100644 --- a/Doc/lib/libre.tex +++ b/Doc/lib/libre.tex @@ -4,7 +4,7 @@ \bimodindex{re} % XXX Remove before 1.5final release. -{\large\bf This documentation is also preliminary and incomplete. If you +{\large\bf This documentation is preliminary and incomplete. If you find a bug or documentation error, or just find something unclear, please send a message to \code{string-sig@python.org}, and we'll fix it.} @@ -485,33 +485,6 @@ The pattern string from which the regex object was compiled. \subsection{MatchObjects} \code{Matchobject} instances support the following methods and attributes: -\begin{funcdesc}{start}{group} -\end{funcdesc} - -\begin{funcdesc}{end}{group} -Return the indices of the start and end of the substring -matched by \var{group}. Return \code{None} if \var{group} exists but -did not contribute to the match. Note that for a match object -\code{m}, and a group \code{g} that did contribute to the match, the -substring matched by group \code{g} is -\bcode\begin{verbatim} - m.string[m.start(g):m.end(g)] -\end{verbatim}\ecode -% -Note too that \code{m.start(\var{group})} will equal -\code{m.end(\var{group})} if \var{group} matched a null string. For example, -after \code{m = re.search('b(c?)', 'cba')}, \code{m.start(0)} is 1, -\code{m.end(0)} is 2, \code{m.start(1)} and \code{m.end(1)} are both -2, and \code{m.start(2)} raises an -\code{IndexError} exception. -\end{funcdesc} - -\begin{funcdesc}{span}{group} -Return the 2-tuple \code{(start(\var{group}), end(\var{group}))}. -Note that if \var{group} did not contribute to the match, this is -\code{(None, None)}. -\end{funcdesc} - \begin{funcdesc}{group}{\optional{g1, g2, ...}} Returns one or more groups of the match. If there is a single \var{index} argument, the result is a single string; if there are @@ -525,6 +498,14 @@ such group exists, the corresponding result is If the regular expression uses the \code{(?P<\var{name}>...)} syntax, the \var{index} arguments may also be strings identifying groups by their group name. + +A moderately complicated example: +\bcode\begin{verbatim} +m = re.match(r"(?P<int>\d+)\.(\d*)", '3.14') +\end{verbatim}\ecode +% +After performing this match, \code{m.group(1)} is \code{'3'}, as is \code{m.group('int')}. +\code{m.group(2)} is \code{'14'}. \end{funcdesc} \begin{funcdesc}{groups}{} @@ -534,6 +515,34 @@ participate in the match have values of \code{None}. If the tuple would only be one element long, a string will be returned instead. \end{funcdesc} +\begin{funcdesc}{start}{group} +\end{funcdesc} + +\begin{funcdesc}{end}{group} +Return the indices of the start and end of the substring +matched by \var{group}. Return \code{None} if \var{group} exists but +did not contribute to the match. For a match object +\code{m}, and a group \code{g} that did contribute to the match, the +substring matched by group \code{g} (equivalent to \code{m.group(g)}) is +\bcode\begin{verbatim} + m.string[m.start(g):m.end(g)] +\end{verbatim}\ecode +% +Note that +\code{m.start(\var{group})} will equal \code{m.end(\var{group})} if +\var{group} matched a null string. For example, after \code{m = +re.search('b(c?)', 'cba')}, \code{m.start(0)} is 1, \code{m.end(0)} is +2, \code{m.start(1)} and \code{m.end(1)} are both 2, and +\code{m.start(2)} raises an \code{IndexError} exception. + +\end{funcdesc} + +\begin{funcdesc}{span}{group} +Return the 2-tuple \code{(start(\var{group}), end(\var{group}))}. +Note that if \var{group} did not contribute to the match, this is +\code{(None, None)}. +\end{funcdesc} + \begin{datadesc}{pos} The value of \var{pos} which was passed to the \code{search} or \code{match} function. This is the index into the @@ -556,5 +565,10 @@ The string passed to \code{match()} or \code{search()}. \end{datadesc} \begin{seealso} -\seetext Jeffrey Friedl, \emph{Mastering Regular Expressions}. +\seetext Jeffrey Friedl, \emph{Mastering Regular Expressions}, +O'Reilly. The Python material in this book dates from before the re +module, but it covers writing good regular expression patterns in +great detail. \end{seealso} + + |