194 lines
6.0 KiB
TeX
194 lines
6.0 KiB
TeX
|
\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}
|