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diff --git a/Doc/libstring.tex b/Doc/libstring.tex new file mode 100644 index 0000000..2bcbdfc --- /dev/null +++ b/Doc/libstring.tex @@ -0,0 +1,193 @@ +\section{Standard Module \sectcode{string}} + +\stmodindex{string} + +This module defines some constants useful for checking character +classes, some exceptions, and some useful string functions. +The constants are: + +\renewcommand{\indexsubitem}{(data in module string)} +\begin{datadesc}{digits} + The string \code{'0123456789'}. +\end{datadesc} + +\begin{datadesc}{hexdigits} + The string \code{'0123456789abcdefABCDEF'}. +\end{datadesc} + +\begin{datadesc}{letters} + The concatenation of the strings \code{lowercase} and + \code{uppercase} described below. +\end{datadesc} + +\begin{datadesc}{lowercase} + A string containing all the characters that are considered lowercase + letters. On most systems this is the string + \code{'abcdefghijklmnopqrstuvwxyz'}. Do not change its definition -- + the effect on the routines \code{upper} and \code{swapcase} is + undefined. +\end{datadesc} + +\begin{datadesc}{octdigits} + The string \code{'01234567'}. +\end{datadesc} + +\begin{datadesc}{uppercase} + A string containing all the characters that are considered uppercase + letters. On most systems this is the string + \code{'ABCDEFGHIJKLMNOPQRSTUVWXYZ'}. Do not change its definition -- + the effect on the routines \code{lower} and \code{swapcase} is + undefined. +\end{datadesc} + +\begin{datadesc}{whitespace} + A string containing all characters that are considered whitespace. + On most systems this includes the characters space, tab, linefeed, + return, formfeed, and vertical tab. Do not change its definition -- + the effect on the routines \code{strip} and \code{split} is + undefined. +\end{datadesc} + +The exceptions are: + +\renewcommand{\indexsubitem}{(exception in module string)} + +\begin{excdesc}{atof_error} +Exception raised by +\code{atof} +when a non-float string argument is detected. +The exception argument is the offending string. +\end{excdesc} + +\begin{excdesc}{atoi_error} +Exception raised by +\code{atoi} +when a non-integer string argument is detected. +The exception argument is the offending string. +\end{excdesc} + +\begin{excdesc}{atol_error} +Exception raised by +\code{atol} +when a non-integer string argument is detected. +The exception argument is the offending string. +\end{excdesc} + +\begin{excdesc}{index_error} +Exception raised by \code{index} when \var{sub} is not found. +The exception argument is undefined (it may be a tuple containing the +offending arguments to \code{index} or it may be the constant string +\code{'substring not found'}). +\end{excdesc} + +The functions are: + +\renewcommand{\indexsubitem}{(in module string)} + +\begin{funcdesc}{atof}{s} +Convert a string to a floating point number. The string must have +the standard syntax for a floating point literal in Python, optionally +preceded by a sign (\samp{+} or \samp{-}). +\end{funcdesc} + +\begin{funcdesc}{atoi}{s} +Convert a string to an integer. The string must consist of one or more +digits, optionally preceded by a sign (\samp{+} or \samp{-}). +\end{funcdesc} + +\begin{funcdesc}{atol}{s} +Convert a string to a long integer. The string must consist of one +or more digits, optionally preceded by a sign (\samp{+} or \samp{-}). +\end{funcdesc} + +\begin{funcdesc}{expandtabs}{s\, tabsize} +Expand tabs in a string, i.e. replace them by one or more spaces, +depending on the current column and the given tab size. The column +number is reset to zero after each newline occurring in the string. +This doesn't understand other non-printing characters or escape +sequences. +\end{funcdesc} + +\begin{funcdesc}{find}{s\, sub\, i} +Return the lowest index in \var{s} not smaller than \var{i} where the +substring \var{sub} is found. Return \code{-1} when \var{sub} +does not occur as a substring of \var{s} with index at least \var{i}. +If \var{i} is omitted, it defaults to \code{0}. If \var{i} is +negative, \code{len(\var{s})} is added. +\end{funcdesc} + +\begin{funcdesc}{rfind}{s\, sub\, i} +Like \code{find} but finds the highest index. +\end{funcdesc} + +\begin{funcdesc}{index}{s\, sub\, i} +Like \code{find} but raise \code{index_error} when the substring is +not found. +\end{funcdesc} + +\begin{funcdesc}{rindex}{s\, sub\, i} +Like \code{rfind} but raise \code{index_error} when the substring is +not found. +\end{funcdesc} + +\begin{funcdesc}{lower}{s} +Convert letters to lower case. +\end{funcdesc} + +\begin{funcdesc}{split}{s} +Returns a list of the whitespace-delimited words of the string +\var{s}. +\end{funcdesc} + +\begin{funcdesc}{splitfields}{s\, sep} + Returns a list containing the fields of the string \var{s}, using + the string \var{sep} as a separator. The list will have one more + items than the number of non-overlapping occurrences of the + separator in the string. Thus, \code{string.splitfields(\var{s}, ' + ')} is not the same as \code{string.split(\var{s})}, as the latter + only returns non-empty words. As a special case, + \code{splitfields(\var{s}, '')} returns \code{[\var{s}]}, for any string + \var{s}. (See also \code{regsub.split()}.) +\end{funcdesc} + +\begin{funcdesc}{join}{words} +Concatenate a list or tuple of words with intervening spaces. +\end{funcdesc} + +\begin{funcdesc}{joinfields}{words\, sep} +Concatenate a list or tuple of words with intervening separators. +It is always true that +\code{string.joinfields(string.splitfields(\var{t}, \var{sep}), \var{sep})} +equals \var{t}. +\end{funcdesc} + +\begin{funcdesc}{strip}{s} +Removes leading and trailing whitespace from the string +\var{s}. +\end{funcdesc} + +\begin{funcdesc}{swapcase}{s} +Converts lower case letters to upper case and vice versa. +\end{funcdesc} + +\begin{funcdesc}{upper}{s} +Convert letters to upper case. +\end{funcdesc} + +\begin{funcdesc}{ljust}{s\, width} +\funcline{rjust}{s\, width} +\funcline{center}{s\, width} +These functions respectively left-justify, right-justify and center a +string in a field of given width. +They return a string that is at least +\var{width} +characters wide, created by padding the string +\var{s} +with spaces until the given width on the right, left or both sides. +The string is never truncated. +\end{funcdesc} + +\begin{funcdesc}{zfill}{s\, width} +Pad a numeric string on the left with zero digits until the given +width is reached. Strings starting with a sign are handled correctly. +\end{funcdesc} |