gh-92728: Restore re.template, but deprecate it (GH-93161)

Revert "bpo-47211: Remove function re.template() and flag re.TEMPLATE (GH-32300)"

This reverts commit b09184bf05.
(cherry picked from commit 16a7e4a0b7)

Co-authored-by: Miro Hrončok <miro@hroncok.cz>
This commit is contained in:
Miss Islington (bot) 2022-05-24 23:32:20 -07:00 committed by GitHub
parent 7a5f190c9f
commit 74b205b3eb
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10 changed files with 65 additions and 5 deletions

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@ -1273,6 +1273,11 @@ Deprecated
is now deprecated. Support will be removed in Python 3.13. (Contributed by
Jingchen Ye in :gh:`90224`.)
* The :func:`re.template` function and the corresponding :const:`re.TEMPLATE`
and :const:`re.T` flags are deprecated, as they were undocumented and
lacked an obvious purpose. They will be removed in Python 3.13.
(Contributed by Serhiy Storchaka and Miro Hrončok in :gh:`92728`.)
Pending Removal in Python 3.12
==============================

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@ -129,7 +129,7 @@ import functools
# public symbols
__all__ = [
"match", "fullmatch", "search", "sub", "subn", "split",
"findall", "finditer", "compile", "purge", "escape",
"findall", "finditer", "compile", "purge", "template", "escape",
"error", "Pattern", "Match", "A", "I", "L", "M", "S", "X", "U",
"ASCII", "IGNORECASE", "LOCALE", "MULTILINE", "DOTALL", "VERBOSE",
"UNICODE", "NOFLAG", "RegexFlag",
@ -148,6 +148,8 @@ class RegexFlag:
MULTILINE = M = _compiler.SRE_FLAG_MULTILINE # make anchors look for newline
DOTALL = S = _compiler.SRE_FLAG_DOTALL # make dot match newline
VERBOSE = X = _compiler.SRE_FLAG_VERBOSE # ignore whitespace and comments
# sre extensions (experimental, don't rely on these)
TEMPLATE = T = _compiler.SRE_FLAG_TEMPLATE # unknown purpose, deprecated
DEBUG = _compiler.SRE_FLAG_DEBUG # dump pattern after compilation
__str__ = object.__str__
_numeric_repr_ = hex
@ -229,6 +231,18 @@ def purge():
_cache.clear()
_compile_repl.cache_clear()
def template(pattern, flags=0):
"Compile a template pattern, returning a Pattern object, deprecated"
import warnings
warnings.warn("The re.template() function is deprecated "
"as it is an undocumented function "
"without an obvious purpose. "
"Use re.compile() instead.",
DeprecationWarning)
with warnings.catch_warnings():
warnings.simplefilter("ignore", DeprecationWarning) # warn just once
return _compile(pattern, flags|T)
# SPECIAL_CHARS
# closing ')', '}' and ']'
# '-' (a range in character set)
@ -270,6 +284,13 @@ def _compile(pattern, flags):
return pattern
if not _compiler.isstring(pattern):
raise TypeError("first argument must be string or compiled pattern")
if flags & T:
import warnings
warnings.warn("The re.TEMPLATE/re.T flag is deprecated "
"as it is an undocumented flag "
"without an obvious purpose. "
"Don't use it.",
DeprecationWarning)
p = _compiler.compile(pattern, flags)
if not (flags & DEBUG):
if len(_cache) >= _MAXCACHE:

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@ -108,6 +108,8 @@ def _compile(data, pattern, flags):
else:
emit(ANY)
elif op in REPEATING_CODES:
if flags & SRE_FLAG_TEMPLATE:
raise error("internal: unsupported template operator %r" % (op,))
if _simple(av[2]):
emit(REPEATING_CODES[op][2])
skip = _len(code); emit(0)

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@ -204,6 +204,7 @@ CH_UNICODE = {
}
# flags
SRE_FLAG_TEMPLATE = 1 # template mode (unknown purpose, deprecated)
SRE_FLAG_IGNORECASE = 2 # case insensitive
SRE_FLAG_LOCALE = 4 # honour system locale
SRE_FLAG_MULTILINE = 8 # treat target as multiline string

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@ -61,11 +61,12 @@ FLAGS = {
"x": SRE_FLAG_VERBOSE,
# extensions
"a": SRE_FLAG_ASCII,
"t": SRE_FLAG_TEMPLATE,
"u": SRE_FLAG_UNICODE,
}
TYPE_FLAGS = SRE_FLAG_ASCII | SRE_FLAG_LOCALE | SRE_FLAG_UNICODE
GLOBAL_FLAGS = SRE_FLAG_DEBUG
GLOBAL_FLAGS = SRE_FLAG_DEBUG | SRE_FLAG_TEMPLATE
class State:
# keeps track of state for parsing

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@ -2417,6 +2417,30 @@ class ReTests(unittest.TestCase):
self.assertTrue(re.fullmatch(r'(?s:(?>.*?\.).*)\Z', "a.txt")) # reproducer
self.assertTrue(re.fullmatch(r'(?s:(?=(?P<g0>.*?\.))(?P=g0).*)\Z', "a.txt"))
def test_template_function_and_flag_is_deprecated(self):
with self.assertWarns(DeprecationWarning) as cm:
template_re1 = re.template(r'a')
self.assertIn('re.template()', str(cm.warning))
self.assertIn('is deprecated', str(cm.warning))
self.assertIn('function', str(cm.warning))
self.assertNotIn('flag', str(cm.warning))
with self.assertWarns(DeprecationWarning) as cm:
# we deliberately use more flags here to test that that still
# triggers the warning
# if paranoid, we could test multiple different combinations,
# but it's probably not worth it
template_re2 = re.compile(r'a', flags=re.TEMPLATE|re.UNICODE)
self.assertIn('re.TEMPLATE', str(cm.warning))
self.assertIn('is deprecated', str(cm.warning))
self.assertIn('flag', str(cm.warning))
self.assertNotIn('function', str(cm.warning))
# while deprecated, is should still function
self.assertEqual(template_re1, template_re2)
self.assertTrue(template_re1.match('ahoy'))
self.assertFalse(template_re1.match('nope'))
def get_debug_out(pat):
with captured_stdout() as out:
@ -2611,11 +2635,11 @@ class PatternReprTests(unittest.TestCase):
"re.IGNORECASE|re.DOTALL|re.VERBOSE|0x100000")
self.assertEqual(
repr(~re.I),
"re.ASCII|re.LOCALE|re.UNICODE|re.MULTILINE|re.DOTALL|re.VERBOSE|re.DEBUG|0x1")
"re.ASCII|re.LOCALE|re.UNICODE|re.MULTILINE|re.DOTALL|re.VERBOSE|re.TEMPLATE|re.DEBUG")
self.assertEqual(repr(~(re.I|re.S|re.X)),
"re.ASCII|re.LOCALE|re.UNICODE|re.MULTILINE|re.DEBUG|0x1")
"re.ASCII|re.LOCALE|re.UNICODE|re.MULTILINE|re.TEMPLATE|re.DEBUG")
self.assertEqual(repr(~(re.I|re.S|re.X|(1<<20))),
"re.ASCII|re.LOCALE|re.UNICODE|re.MULTILINE|re.DEBUG|0xffe01")
"re.ASCII|re.LOCALE|re.UNICODE|re.MULTILINE|re.TEMPLATE|re.DEBUG|0xffe00")
class ImplementationTest(unittest.TestCase):

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@ -1373,6 +1373,7 @@ Suppress expression chaining for more :mod:`re` parsing errors.
Remove undocumented and never working function ``re.template()`` and flag
``re.TEMPLATE``.
This was later reverted in 3.11.0b2 and deprecated instead.
..

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@ -0,0 +1,3 @@
The :func:`re.template` function and the corresponding :const:`re.TEMPLATE`
and :const:`re.T` flags are restored after they were removed in 3.11.0b1,
but they are now deprecated, so they might be removed from Python 3.13.

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@ -1323,6 +1323,7 @@ pattern_repr(PatternObject *obj)
const char *name;
int value;
} flag_names[] = {
{"re.TEMPLATE", SRE_FLAG_TEMPLATE},
{"re.IGNORECASE", SRE_FLAG_IGNORECASE},
{"re.LOCALE", SRE_FLAG_LOCALE},
{"re.MULTILINE", SRE_FLAG_MULTILINE},

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@ -85,6 +85,7 @@
#define SRE_CATEGORY_UNI_NOT_WORD 15
#define SRE_CATEGORY_UNI_LINEBREAK 16
#define SRE_CATEGORY_UNI_NOT_LINEBREAK 17
#define SRE_FLAG_TEMPLATE 1
#define SRE_FLAG_IGNORECASE 2
#define SRE_FLAG_LOCALE 4
#define SRE_FLAG_MULTILINE 8