Standard Module string

string This module defines some constants useful for checking character classes, some exceptions, and some useful string functions. The constants are:
$\begin{datadesc}{digits} The string \code{'0123456789'}. \end{datadesc}$

$\begin{datadesc}{hexdigits} The string \code{'0123456789abcdefABCDEF'}. \end{datadesc}$

$\begin{datadesc}{letters} The concatenation of the strings \code{lowercase} and \code{uppercase} described below. \end{datadesc}$

$\begin{datadesc}{lowercase} A string containing all the characters that are con... ...t on the routines \code{upper} and \code{swapcase} is undefined. \end{datadesc}$

$\begin{datadesc}{octdigits} The string \code{'01234567'}. \end{datadesc}$

$\begin{datadesc}{uppercase} A string containing all the characters that are con... ...t on the routines \code{lower} and \code{swapcase} is undefined. \end{datadesc}$

$\begin{datadesc}{whitespace} A string containing all characters that are consid... ...fect on the routines \code{strip} and \code{split} is undefined. \end{datadesc}$
The exceptions are: The functions are:
$\begin{funcdesc}{atof}{s} Convert a string to a floating point number. The strin... ... in Python, optionally preceded by a sign (\samp{+} or \samp{-}). \end{funcdesc}$

$\begin{funcdesc}{atoi}{s} Convert a string to an integer. The string must consis... ...ore digits, optionally preceded by a sign (\samp{+} or \samp{-}). \end{funcdesc}$

$\begin{funcdesc}{atol}{s} Convert a string to a long integer. The string must co... ...ore digits, optionally preceded by a sign (\samp{+} or \samp{-}). \end{funcdesc}$

$\begin{funcdesc}{expandtabs}{s\, tabsize} Expand tabs in a string, i.e. replace ... ...n't understand other non-printing characters or escape sequences. \end{funcdesc}$

$\begin{funcdesc}{find}{s\, sub\optional{\, start}} Return the lowest index in \v... ...ode{0}. If \var{start} is negative, \code{len(\var{s})} is added. \end{funcdesc}$

$\begin{funcdesc}{rfind}{s\, sub\optional{\, start}} Like \code{find} but finds the highest index. \end{funcdesc}$

$\begin{funcdesc}{index}{s\, sub\optional{\, start}} Like \code{find} but raise \code{ValueError} when the substring is not found. \end{funcdesc}$

$\begin{funcdesc}{rindex}{s\, sub\optional{\, start}} Like \code{rfind} but raise \code{ValueError} when the substring is not found. \end{funcdesc}$

$\begin{funcdesc}{count}{s\, sub\, i} Return the number of (non-overlapping) occu... ...at least \var{i}. If \var{i} is omitted, it defaults to \code{0}. \end{funcdesc}$

$\begin{funcdesc}{lower}{s} Convert letters to lower case. \end{funcdesc}$

$\begin{funcdesc}{split}{s} Returns a list of the whitespace-delimited words of the string \var{s}. \end{funcdesc}$

$\begin{funcdesc}{splitfields}{s\, sep} Returns a list containing the fields of ... ...{s}]}, for any string \var{s}. (See also \code{regsub.split()}.) \end{funcdesc}$

$\begin{funcdesc}{join}{words} Concatenate a list or tuple of words with intervening spaces. \end{funcdesc}$

$\begin{funcdesc}{joinfields}{words\, sep} Concatenate a list or tuple of words w... ...ring.splitfields(\var{t}, \var{sep}), \var{sep})} equals \var{t}. \end{funcdesc}$

$\begin{funcdesc}{strip}{s} Removes leading and trailing whitespace from the string \var{s}. \end{funcdesc}$

$\begin{funcdesc}{swapcase}{s} Converts lower case letters to upper case and vice versa. \end{funcdesc}$

$\begin{funcdesc}{upper}{s} Convert letters to upper case. \end{funcdesc}$

$\begin{funcdesc}{ljust}{s\, width} \funcline{rjust}{s\, width} \funcline{center}... ... on the right, left or both sides. The string is never truncated. \end{funcdesc}$

$\begin{funcdesc}{zfill}{s\, width} Pad a numeric string on the left with zero di... ...h is reached. Strings starting with a sign are handled correctly. \end{funcdesc}$