mirror of https://github.com/python/cpython
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>.
This commit is contained in:
Fred Drake
parent
3b02ddfa41
commit
e848976fba
|
|
@ -57,187 +57,191 @@ The functions defined in this module are:
|
|||
|
||||
|
||||
\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
|
||||
|
|
|
|||
Loading…
Reference in New Issue