mirror of https://github.com/python/cpython
fixed character set description in docstring (SRE uses Python
strings, not C strings) removed USE_PYTHON defines, and related sre.py helpers skip calling the subx helper if the template is callable. interestingly enough, this means that def callback(m): return literal result = pattern.sub(callback, string) is much faster than result = pattern.sub(literal, string)
This commit is contained in:
Fredrik Lundh
parent
0402dd18cb
commit
dac58492aa
81
Lib/sre.py
81
Lib/sre.py
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@ -17,15 +17,13 @@
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r"""Support for regular expressions (RE).
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This module provides regular expression matching operations similar to
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those found in Perl. It's 8-bit clean: the strings being processed may
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contain both null bytes and characters whose high bit is set. Regular
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expression pattern strings may not contain null bytes, but can specify
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the null byte using the \\number notation. Characters with the high
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bit set may be included.
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those found in Perl. It supports both 8-bit and Unicode strings; both
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the pattern and the strings being processed can contain null bytes and
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characters outside the US ASCII range.
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Regular expressions can contain both special and ordinary
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characters. Most ordinary characters, like "A", "a", or "0", are the
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simplest regular expressions; they simply match themselves. You can
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Regular expressions can contain both special and ordinary characters.
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Most ordinary characters, like "A", "a", or "0", are the simplest
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regular expressions; they simply match themselves. You can
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concatenate ordinary characters, so last matches the string 'last'.
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The special characters are:
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@ -45,7 +43,7 @@ The special characters are:
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"|" A|B, creates an RE that will match either A or B.
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(...) Matches the RE inside the parentheses.
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The contents can be retrieved or matched later in the string.
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(?iLmsx) Set the I, L, M, S, or X flag for the RE (see below).
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(?iLmsux) Set the I, L, M, S, U, or X flag for the RE (see below).
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(?:...) Non-grouping version of regular parentheses.
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(?P<name>...) The substring matched by the group is accessible by name.
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(?P=name) Matches the text matched earlier by the group named name.
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@ -246,77 +244,14 @@ def _expand(pattern, match, template):
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def _subx(pattern, template):
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# internal: pattern.sub/subn implementation helper
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if callable(template):
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filter = template
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else:
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template = _compile_repl(template, pattern)
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if not template[0] and len(template[1]) == 1:
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# literal replacement
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filter = template[1][0]
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else:
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return template[1][0]
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def filter(match, template=template):
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return sre_parse.expand_template(template, match)
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return filter
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def _sub(pattern, template, text, count=0):
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# internal: pattern.sub implementation hook
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# FIXME: not used in SRE 2.2.1 and later; will be removed soon
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return _subn(pattern, template, text, count)[0]
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def _subn(pattern, template, text, count=0):
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# internal: pattern.subn implementation hook
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# FIXME: not used in SRE 2.2.1 and later; will be removed soon
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filter = _subx(pattern, template)
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if not callable(filter):
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# literal replacement
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def filter(match, literal=filter):
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return literal
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n = i = 0
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s = []
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append = s.append
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c = pattern.scanner(text)
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while not count or n < count:
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m = c.search()
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if not m:
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break
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b, e = m.span()
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if i < b:
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append(text[i:b])
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elif i == b == e and n:
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append(text[i:b])
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continue # ignore empty match at previous position
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append(filter(m))
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i = e
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n = n + 1
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append(text[i:])
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return _join(s, text[:0]), n
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def _split(pattern, text, maxsplit=0):
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# internal: pattern.split implementation hook
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# FIXME: not used in SRE 2.2.1 and later; will be removed soon
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n = i = 0
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s = []
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append = s.append
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extend = s.extend
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c = pattern.scanner(text)
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g = pattern.groups
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while not maxsplit or n < maxsplit:
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m = c.search()
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if not m:
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break
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b, e = m.span()
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if b == e:
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if i >= len(text):
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break
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continue
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append(text[i:b])
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if g and b != e:
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extend(list(m.groups()))
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i = e
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n = n + 1
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append(text[i:])
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return s
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# register myself for pickling
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import copy_reg
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@ -76,10 +76,6 @@ static char copyright[] =
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/* -------------------------------------------------------------------- */
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/* optional features */
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/* test: define to use sre.py helpers instead of C code */
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#undef USE_PYTHON_SPLIT
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#undef USE_PYTHON_SUB
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/* prevent run-away recursion (bad patterns on long strings) */
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#if !defined(USE_STACKCHECK)
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@ -1251,6 +1247,8 @@ SRE_SEARCH(SRE_STATE* state, SRE_CODE* pattern)
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TRACE(("|%p|%p|SEARCH LITERAL\n", pattern, ptr));
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state->start = ptr;
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state->ptr = ++ptr;
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if (flags & SRE_INFO_LITERAL)
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return 1; /* we got all of it */
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status = SRE_MATCH(state, pattern + 2, 1);
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if (status != 0)
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break;
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@ -1820,66 +1818,6 @@ join(PyObject* list, PyObject* pattern)
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return result;
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}
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#ifdef USE_PYTHON_SUB
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static PyObject*
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pattern_sub(PatternObject* self, PyObject* args, PyObject* kw)
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{
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PyObject* template;
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PyObject* string;
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PyObject* count = Py_False; /* zero */
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static char* kwlist[] = { "repl", "string", "count", NULL };
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if (!PyArg_ParseTupleAndKeywords(args, kw, "OO|O:sub", kwlist,
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&template, &string, &count))
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return NULL;
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/* delegate to Python code */
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return call(
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SRE_MODULE, "_sub",
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Py_BuildValue("OOOO", self, template, string, count)
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);
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}
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#endif
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#ifdef USE_PYTHON_SUB
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static PyObject*
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pattern_subn(PatternObject* self, PyObject* args, PyObject* kw)
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{
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PyObject* template;
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PyObject* string;
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PyObject* count = Py_False; /* zero */
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static char* kwlist[] = { "repl", "string", "count", NULL };
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if (!PyArg_ParseTupleAndKeywords(args, kw, "OO|O:subn", kwlist,
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&template, &string, &count))
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return NULL;
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/* delegate to Python code */
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return call(
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SRE_MODULE, "_subn",
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Py_BuildValue("OOOO", self, template, string, count)
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);
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}
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#endif
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#if defined(USE_PYTHON_SPLIT)
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static PyObject*
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pattern_split(PatternObject* self, PyObject* args, PyObject* kw)
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{
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PyObject* string;
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PyObject* maxsplit = Py_False; /* zero */
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static char* kwlist[] = { "source", "maxsplit", NULL };
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if (!PyArg_ParseTupleAndKeywords(args, kw, "O|O:split", kwlist,
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&string, &maxsplit))
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return NULL;
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/* delegate to Python code */
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return call(
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SRE_MODULE, "_split",
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Py_BuildValue("OOO", self, string, maxsplit)
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);
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}
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#endif
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static PyObject*
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pattern_findall(PatternObject* self, PyObject* args, PyObject* kw)
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{
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@ -1980,7 +1918,6 @@ error:
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}
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#if !defined(USE_PYTHON_SPLIT)
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static PyObject*
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pattern_split(PatternObject* self, PyObject* args, PyObject* kw)
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{
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@ -2071,15 +2008,16 @@ pattern_split(PatternObject* self, PyObject* args, PyObject* kw)
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}
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/* get segment following last match */
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item = PySequence_GetSlice(
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string, STATE_OFFSET(&state, last), state.endpos
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);
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i = STATE_OFFSET(&state, last);
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if (i < state.endpos) {
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item = PySequence_GetSlice(string, i, state.endpos);
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if (!item)
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goto error;
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status = PyList_Append(list, item);
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Py_DECREF(item);
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if (status < 0)
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goto error;
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}
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state_fini(&state);
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return list;
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@ -2090,9 +2028,7 @@ error:
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return NULL;
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}
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#endif
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#if !defined(USE_PYTHON_SUB)
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static PyObject*
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pattern_subx(PatternObject* self, PyObject* template, PyObject* string,
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int count, int subn)
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@ -2108,15 +2044,22 @@ pattern_subx(PatternObject* self, PyObject* template, PyObject* string,
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int i, b, e;
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int filter_is_callable;
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/* call subx helper to get the filter */
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if (PyCallable_Check(template)) {
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/* sub/subn takes either a function or a template */
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filter = template;
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Py_INCREF(filter);
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filter_is_callable = 1;
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} else {
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/* if not callable, call the template compiler. it may return
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either a filter function or a literal string */
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filter = call(
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SRE_MODULE, "_subx",
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Py_BuildValue("OO", self, template)
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);
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if (!filter)
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return NULL;
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filter_is_callable = PyCallable_Check(filter);
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}
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string = state_init(&state, self, string, 0, INT_MAX);
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if (!string)
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@ -2169,7 +2112,7 @@ pattern_subx(PatternObject* self, PyObject* template, PyObject* string,
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goto next;
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if (filter_is_callable) {
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/* filter match */
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/* pass match object through filter */
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match = pattern_new_match(self, &state, 1);
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if (!match)
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goto error;
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@ -2186,7 +2129,7 @@ pattern_subx(PatternObject* self, PyObject* template, PyObject* string,
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} else {
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/* filter is literal string */
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item = filter;
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Py_INCREF(filter);
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Py_INCREF(item);
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}
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/* add to list */
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@ -2208,6 +2151,7 @@ next:
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}
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/* get segment following last match */
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if (i < state.endpos) {
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item = PySequence_GetSlice(string, i, state.endpos);
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if (!item)
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goto error;
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@ -2215,11 +2159,13 @@ next:
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Py_DECREF(item);
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if (status < 0)
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goto error;
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}
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state_fini(&state);
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/* convert list to single string */
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/* convert list to single string (also removes list) */
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item = join(list, self->pattern);
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if (!item)
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return NULL;
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@ -2262,7 +2208,6 @@ pattern_subn(PatternObject* self, PyObject* args, PyObject* kw)
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return pattern_subx(self, template, string, count, 1);
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}
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#endif
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static PyObject*
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pattern_copy(PatternObject* self, PyObject* args)
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