Added an example of a string value for the replacement parameter to
re.sub(). This closes SF bug #446136. Fixed description of RE modifiers so that RE{#} and RE{#,} are more clearly described and disambiguated (plain RE{#} had not been described at all). Reported by Jeremy Craven via email.
This commit is contained in:
Fred Drake
parent
630a63cafd
commit
e74f8de385
|
|
@ -128,11 +128,19 @@ perform the match in \dfn{non-greedy} or \dfn{minimal} fashion; as
|
|||
\emph{few} characters as possible will be matched. Using \regexp{.*?}
|
||||
in the previous expression will match only \code{'<H1>'}.
|
||||
|
||||
\item[\code{\{\var{m}\}}]
|
||||
Specifies that exactly \var{m} copies of the previous RE should be
|
||||
matched; fewer matches cause the entire RE not to match. For example,
|
||||
\regexp{a\{6\}} will match exactly six \character{a} characters, but
|
||||
not five.
|
||||
|
||||
\item[\code{\{\var{m},\var{n}\}}] Causes the resulting RE to match from
|
||||
\var{m} to \var{n} repetitions of the preceding RE, attempting to
|
||||
match as many repetitions as possible. For example, \regexp{a\{3,5\}}
|
||||
will match from 3 to 5 \character{a} characters. Omitting \var{n}
|
||||
specifies an infinite upper bound; you can't omit \var{m}.
|
||||
specifies an infinite upper bound; you can't omit \var{m}. The comma
|
||||
may not be omitted or the modifier would be confused with the
|
||||
previously described form.
|
||||
|
||||
\item[\code{\{\var{m},\var{n}\}?}] Causes the resulting RE to
|
||||
match from \var{m} to \var{n} repetitions of the preceding RE,
|
||||
|
|
@ -497,21 +505,36 @@ ignored.
|
|||
\end{funcdesc}
|
||||
|
||||
\begin{funcdesc}{findall}{pattern, string}
|
||||
Return a list of all non-overlapping matches of \var{pattern} in
|
||||
\var{string}. If one or more groups are present in the pattern,
|
||||
return a list of groups; this will be a list of tuples if the pattern
|
||||
has more than one group. Empty matches are included in the result.
|
||||
\versionadded{1.5.2}
|
||||
Return a list of all non-overlapping matches of \var{pattern} in
|
||||
\var{string}. If one or more groups are present in the pattern,
|
||||
return a list of groups; this will be a list of tuples if the
|
||||
pattern has more than one group. Empty matches are included in the
|
||||
result.
|
||||
\versionadded{1.5.2}
|
||||
\end{funcdesc}
|
||||
|
||||
\begin{funcdesc}{sub}{pattern, repl, string\optional{, count\code{ = 0}}}
|
||||
Return the string obtained by replacing the leftmost non-overlapping
|
||||
occurrences of \var{pattern} in \var{string} by the replacement
|
||||
\var{repl}. If the pattern isn't found, \var{string} is returned
|
||||
unchanged. \var{repl} can be a string or a function; if a function,
|
||||
it is called for every non-overlapping occurrence of \var{pattern}.
|
||||
The function takes a single match object argument, and returns the
|
||||
replacement string. For example:
|
||||
\begin{funcdesc}{sub}{pattern, repl, string\optional{, count}}
|
||||
Return the string obtained by replacing the leftmost non-overlapping
|
||||
occurrences of \var{pattern} in \var{string} by the replacement
|
||||
\var{repl}. If the pattern isn't found, \var{string} is returned
|
||||
unchanged. \var{repl} can be a string or a function; if it is a
|
||||
string, any backslash escapes in it are processed. That is,
|
||||
\samp{\e n} is converted to a single newline character, \samp{\e r}
|
||||
is converted to a linefeed, and so forth. Unknown escapes such as
|
||||
\samp{\e j} are left alone. Backreferences, such as \samp{\e6}, are
|
||||
replaced with the substring matched by group 6 in the pattern. For
|
||||
example:
|
||||
|
||||
\begin{verbatim}
|
||||
>>> re.sub(r'def\s+([a-zA-Z_][a-zA-Z_0-9]*)\s*\(\s*\):',
|
||||
... r'static PyObject*\npy_\1(void)\n{',
|
||||
... 'def myfunc():')
|
||||
'static PyObject*\npy_myfunc(void)\n{'
|
||||
\end{verbatim}
|
||||
|
||||
If \var{repl} is a function, it is called for every non-overlapping
|
||||
occurrence of \var{pattern}. The function takes a single match
|
||||
object argument, and returns the replacement string. For example:
|
||||
|
||||
\begin{verbatim}
|
||||
>>> def dashrepl(matchobj):
|
||||
|
|
@ -521,38 +544,31 @@ replacement string. For example:
|
|||
'pro--gram files'
|
||||
\end{verbatim}
|
||||
|
||||
The pattern may be a string or an RE object; if you need to specify
|
||||
regular expression flags, you must use a RE object, or use
|
||||
embedded modifiers in a pattern; for example,
|
||||
\samp{sub("(?i)b+", "x", "bbbb BBBB")} returns \code{'x x'}.
|
||||
The pattern may be a string or an RE object; if you need to specify
|
||||
regular expression flags, you must use a RE object, or use embedded
|
||||
modifiers in a pattern; for example, \samp{sub("(?i)b+", "x", "bbbb
|
||||
BBBB")} returns \code{'x x'}.
|
||||
|
||||
The optional argument \var{count} is the maximum number of pattern
|
||||
occurrences to be replaced; \var{count} must be a non-negative
|
||||
integer, and the default value of 0 means to replace all occurrences.
|
||||
The optional argument \var{count} is the maximum number of pattern
|
||||
occurrences to be replaced; \var{count} must be a non-negative
|
||||
integer. If omitted or zero, all occurrences will be replaced.
|
||||
Empty matches for the pattern are replaced only when not adjacent to
|
||||
a previous match, so \samp{sub('x*', '-', 'abc')} returns
|
||||
\code{'-a-b-c-'}.
|
||||
|
||||
Empty matches for the pattern are replaced only when not adjacent to a
|
||||
previous match, so \samp{sub('x*', '-', 'abc')} returns
|
||||
\code{'-a-b-c-'}.
|
||||
|
||||
If \var{repl} is a string, any backslash escapes in it are processed.
|
||||
That is, \samp{\e n} is converted to a single newline character,
|
||||
\samp{\e r} is converted to a linefeed, and so forth. Unknown escapes
|
||||
such as \samp{\e j} are left alone. Backreferences, such as \samp{\e
|
||||
6}, are replaced with the substring matched by group 6 in the pattern.
|
||||
|
||||
In addition to character escapes and backreferences as described
|
||||
above, \samp{\e g<name>} will use the substring matched by the group
|
||||
named \samp{name}, as defined by the \regexp{(?P<name>...)} syntax.
|
||||
\samp{\e g<number>} uses the corresponding group number; \samp{\e
|
||||
g<2>} is therefore equivalent to \samp{\e 2}, but isn't ambiguous in a
|
||||
replacement such as \samp{\e g<2>0}. \samp{\e 20} would be
|
||||
interpreted as a reference to group 20, not a reference to group 2
|
||||
followed by the literal character \character{0}.
|
||||
In addition to character escapes and backreferences as described
|
||||
above, \samp{\e g<name>} will use the substring matched by the group
|
||||
named \samp{name}, as defined by the \regexp{(?P<name>...)} syntax.
|
||||
\samp{\e g<number>} uses the corresponding group number;
|
||||
\samp{\e g<2>} is therefore equivalent to \samp{\e 2}, but isn't
|
||||
ambiguous in a replacement such as \samp{\e g<2>0}. \samp{\e 20}
|
||||
would be interpreted as a reference to group 20, not a reference to
|
||||
group 2 followed by the literal character \character{0}.
|
||||
\end{funcdesc}
|
||||
|
||||
\begin{funcdesc}{subn}{pattern, repl, string\optional{, count\code{ = 0}}}
|
||||
Perform the same operation as \function{sub()}, but return a tuple
|
||||
\code{(\var{new_string}, \var{number_of_subs_made})}.
|
||||
\begin{funcdesc}{subn}{pattern, repl, string\optional{, count}}
|
||||
Perform the same operation as \function{sub()}, but return a tuple
|
||||
\code{(\var{new_string}, \var{number_of_subs_made})}.
|
||||
\end{funcdesc}
|
||||
|
||||
\begin{funcdesc}{escape}{string}
|
||||
|
|
|
|||
Loading…
Reference in New Issue