Clarify descriptions of some operations; it's not always clear that
strings are not actually modified. Problem reported by Dr. Peter
Stoehr <peter.stoehr@weihenstephan.org>.
diff --git a/Doc/lib/libstring.tex b/Doc/lib/libstring.tex
index f7189fd..4bf2903 100644
--- a/Doc/lib/libstring.tex
+++ b/Doc/lib/libstring.tex
@@ -57,187 +57,191 @@
\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{-}). Note that this behaves
-identical to the built-in function
-\function{float()}\bifuncindex{float} when passed a string.
+ 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{-}). Note that
+ this behaves identical to the built-in function
+ \function{float()}\bifuncindex{float} when passed a string.
\end{funcdesc}
\begin{funcdesc}{atoi}{s\optional{, base}}
-Convert string \var{s} to an integer in the given \var{base}. The
-string must consist of one or more digits, optionally preceded by a
-sign (\samp{+} or \samp{-}). The \var{base} defaults to 10. If it is
-0, a default base is chosen depending on the leading characters of the
-string (after stripping the sign): \samp{0x} or \samp{0X} means 16,
-\samp{0} means 8, anything else means 10. If \var{base} is 16, a
-leading \samp{0x} or \samp{0X} is always accepted. Note that when
-invoked without \var{base} or with \var{base} set to 10, this behaves
-identical to the built-in function \function{int()} when passed a string.
-(Also note: for a more flexible interpretation of numeric literals,
-use the built-in function \function{eval()}\bifuncindex{eval}.)
+ Convert string \var{s} to an integer in the given \var{base}. The
+ string must consist of one or more digits, optionally preceded by a
+ sign (\samp{+} or \samp{-}). The \var{base} defaults to 10. If it
+ is 0, a default base is chosen depending on the leading characters
+ of the string (after stripping the sign): \samp{0x} or \samp{0X}
+ means 16, \samp{0} means 8, anything else means 10. If \var{base}
+ is 16, a leading \samp{0x} or \samp{0X} is always accepted. Note
+ that when invoked without \var{base} or with \var{base} set to 10,
+ this behaves identical to the built-in function \function{int()}
+ when passed a string. (Also note: for a more flexible
+ interpretation of numeric literals, use the built-in function
+ \function{eval()}\bifuncindex{eval}.)
\end{funcdesc}
\begin{funcdesc}{atol}{s\optional{, base}}
-Convert string \var{s} to a long integer in the given \var{base}. The
-string must consist of one or more digits, optionally preceded by a
-sign (\samp{+} or \samp{-}). The \var{base} argument has the same
-meaning as for \function{atoi()}. A trailing \samp{l} or \samp{L} is
-not allowed, except if the base is 0. Note that when invoked without
-\var{base} or with \var{base} set to 10, this behaves identical to the
-built-in function \function{long()}\bifuncindex{long} when passed a
-string.
+ Convert string \var{s} to a long integer in the given \var{base}.
+ The string must consist of one or more digits, optionally preceded
+ by a sign (\samp{+} or \samp{-}). The \var{base} argument has the
+ same meaning as for \function{atoi()}. A trailing \samp{l} or
+ \samp{L} is not allowed, except if the base is 0. Note that when
+ invoked without \var{base} or with \var{base} set to 10, this
+ behaves identical to the built-in function
+ \function{long()}\bifuncindex{long} when passed a string.
\end{funcdesc}
\begin{funcdesc}{capitalize}{word}
-Capitalize the first character of the argument.
+ Capitalize the first character of the argument.
\end{funcdesc}
\begin{funcdesc}{capwords}{s}
-Split the argument into words using \function{split()}, capitalize
-each word using \function{capitalize()}, and join the capitalized
-words using \function{join()}. Note that this replaces runs of
-whitespace characters by a single space, and removes leading and
-trailing whitespace.
+ Split the argument into words using \function{split()}, capitalize
+ each word using \function{capitalize()}, and join the capitalized
+ words using \function{join()}. Note that this replaces runs of
+ whitespace characters by a single space, and removes leading and
+ trailing whitespace.
\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.
+ 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\optional{, start\optional{,end}}}
-Return the lowest index in \var{s} where the substring \var{sub} is
-found such that \var{sub} is wholly contained in
-\code{\var{s}[\var{start}:\var{end}]}. Return \code{-1} on failure.
-Defaults for \var{start} and \var{end} and interpretation of negative
-values is the same as for slices.
+ Return the lowest index in \var{s} where the substring \var{sub} is
+ found such that \var{sub} is wholly contained in
+ \code{\var{s}[\var{start}:\var{end}]}. Return \code{-1} on failure.
+ Defaults for \var{start} and \var{end} and interpretation of
+ negative values is the same as for slices.
\end{funcdesc}
\begin{funcdesc}{rfind}{s, sub\optional{, start\optional{, end}}}
-Like \function{find()} but find the highest index.
+ Like \function{find()} but find the highest index.
\end{funcdesc}
\begin{funcdesc}{index}{s, sub\optional{, start\optional{, end}}}
-Like \function{find()} but raise \exception{ValueError} when the
-substring is not found.
+ Like \function{find()} but raise \exception{ValueError} when the
+ substring is not found.
\end{funcdesc}
\begin{funcdesc}{rindex}{s, sub\optional{, start\optional{, end}}}
-Like \function{rfind()} but raise \exception{ValueError} when the
-substring is not found.
+ Like \function{rfind()} but raise \exception{ValueError} when the
+ substring is not found.
\end{funcdesc}
\begin{funcdesc}{count}{s, sub\optional{, start\optional{, end}}}
-Return the number of (non-overlapping) occurrences of substring
-\var{sub} in string \code{\var{s}[\var{start}:\var{end}]}.
-Defaults for \var{start} and \var{end} and interpretation of negative
-values is the same as for slices.
+ Return the number of (non-overlapping) occurrences of substring
+ \var{sub} in string \code{\var{s}[\var{start}:\var{end}]}.
+ Defaults for \var{start} and \var{end} and interpretation of
+ negative values is the same as for slices.
\end{funcdesc}
\begin{funcdesc}{lower}{s}
-Convert letters to lower case.
+ Return a copy of \var{s}, but with upper case letters converted to
+ lower case.
\end{funcdesc}
\begin{funcdesc}{maketrans}{from, to}
-Return a translation table suitable for passing to
-\function{translate()} or \function{regex.compile()}, that will map
-each character in \var{from} into the character at the same position
-in \var{to}; \var{from} and \var{to} must have the same length.
+ Return a translation table suitable for passing to
+ \function{translate()} or \function{regex.compile()}, that will map
+ each character in \var{from} into the character at the same position
+ in \var{to}; \var{from} and \var{to} must have the same length.
-\strong{Warning:} don't use strings derived from \code{lowercase} and
-\code{uppercase} as arguments; in some locales, these don't have the
-same length. For case conversions, always use \function{lower()} and
-\function{upper()}.
+ \strong{Warning:} don't use strings derived from \code{lowercase}
+ and \code{uppercase} as arguments; in some locales, these don't have
+ the same length. For case conversions, always use
+ \function{lower()} and \function{upper()}.
\end{funcdesc}
\begin{funcdesc}{split}{s\optional{, sep\optional{, maxsplit}}}
-Return a list of the words of the string \var{s}. If the optional
-second argument \var{sep} is absent or \code{None}, the words are
-separated by arbitrary strings of whitespace characters (space, tab,
-newline, return, formfeed). If the second argument \var{sep} is
-present and not \code{None}, it specifies a string to be used as the
-word separator. The returned list will then have one more items than
-the number of non-overlapping occurrences of the separator in the
-string. The optional third argument \var{maxsplit} defaults to 0. If
-it is nonzero, at most \var{maxsplit} number of splits occur, and the
-remainder of the string is returned as the final element of the list
-(thus, the list will have at most \code{\var{maxsplit}+1} elements).
+ Return a list of the words of the string \var{s}. If the optional
+ second argument \var{sep} is absent or \code{None}, the words are
+ separated by arbitrary strings of whitespace characters (space, tab,
+ newline, return, formfeed). If the second argument \var{sep} is
+ present and not \code{None}, it specifies a string to be used as the
+ word separator. The returned list will then have one more items
+ than the number of non-overlapping occurrences of the separator in
+ the string. The optional third argument \var{maxsplit} defaults to
+ 0. If it is nonzero, at most \var{maxsplit} number of splits occur,
+ and the remainder of the string is returned as the final element of
+ the list (thus, the list will have at most \code{\var{maxsplit}+1}
+ elements).
\end{funcdesc}
\begin{funcdesc}{splitfields}{s\optional{, sep\optional{, maxsplit}}}
-This function behaves identically to \function{split()}. (In the
-past, \function{split()} was only used with one argument, while
-\function{splitfields()} was only used with two arguments.)
+ This function behaves identically to \function{split()}. (In the
+ past, \function{split()} was only used with one argument, while
+ \function{splitfields()} was only used with two arguments.)
\end{funcdesc}
\begin{funcdesc}{join}{words\optional{, sep}}
-Concatenate a list or tuple of words with intervening occurrences of
-\var{sep}. The default value for \var{sep} is a single space
-character. It is always true that
-\samp{string.join(string.split(\var{s}, \var{sep}), \var{sep})}
-equals \var{s}.
+ Concatenate a list or tuple of words with intervening occurrences of
+ \var{sep}. The default value for \var{sep} is a single space
+ character. It is always true that
+ \samp{string.join(string.split(\var{s}, \var{sep}), \var{sep})}
+ equals \var{s}.
\end{funcdesc}
\begin{funcdesc}{joinfields}{words\optional{, sep}}
-This function behaves identical to \function{join()}. (In the past,
-\function{join()} was only used with one argument, while
-\function{joinfields()} was only used with two arguments.)
+ This function behaves identical to \function{join()}. (In the past,
+ \function{join()} was only used with one argument, while
+ \function{joinfields()} was only used with two arguments.)
\end{funcdesc}
\begin{funcdesc}{lstrip}{s}
-Remove leading whitespace from the string \var{s}.
+ Return a copy of \var{s} but without leading whitespace characters.
\end{funcdesc}
\begin{funcdesc}{rstrip}{s}
-Remove trailing whitespace from the string \var{s}.
+ Return a copy of \var{s} but without trailing whitespace
+ characters.
\end{funcdesc}
\begin{funcdesc}{strip}{s}
-Remove leading and trailing whitespace from the string \var{s}.
+ Return a copy of \var{s} without leading or trailing whitespace.
\end{funcdesc}
\begin{funcdesc}{swapcase}{s}
-Convert lower case letters to upper case and vice versa.
+ Return a copy of \var{s}, but with lower case letters
+ converted to upper case and vice versa.
\end{funcdesc}
\begin{funcdesc}{translate}{s, table\optional{, deletechars}}
-Delete all characters from \var{s} that are in \var{deletechars} (if
-present), and then translate the characters using \var{table}, which
-must be a 256-character string giving the translation for each
-character value, indexed by its ordinal.
+ Delete all characters from \var{s} that are in \var{deletechars} (if
+ present), and then translate the characters using \var{table}, which
+ must be a 256-character string giving the translation for each
+ character value, indexed by its ordinal.
\end{funcdesc}
\begin{funcdesc}{upper}{s}
-Convert letters to upper case.
+ Return a copy of \var{s}, but with lower case letters converted 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.
+ 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.
+ 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}
\begin{funcdesc}{replace}{str, old, new\optional{, maxsplit}}
-Return a copy of string \var{str} with all occurrences of substring
-\var{old} replaced by \var{new}. If the optional argument
-\var{maxsplit} is given, the first \var{maxsplit} occurrences are
-replaced.
+ Return a copy of string \var{str} with all occurrences of substring
+ \var{old} replaced by \var{new}. If the optional argument
+ \var{maxsplit} is given, the first \var{maxsplit} occurrences are
+ replaced.
\end{funcdesc}
This module is implemented in Python. Much of its functionality has