[Python-checkins] gh-91760: Deprecate group names and numbers which will be invalid in future (GH-91794)
serhiy-storchaka
webhook-mailer at python.org
Sat Apr 30 06:13:50 EDT 2022
https://github.com/python/cpython/commit/19dca041212f9f58ee11833bff3f8c157d4fd3e8
commit: 19dca041212f9f58ee11833bff3f8c157d4fd3e8
branch: main
author: Serhiy Storchaka <storchaka at gmail.com>
committer: serhiy-storchaka <storchaka at gmail.com>
date: 2022-04-30T13:13:46+03:00
summary:
gh-91760: Deprecate group names and numbers which will be invalid in future (GH-91794)
Only sequence of ASCII digits will be accepted as a numerical reference.
The group name in bytes patterns and replacement strings could only
contain ASCII letters and digits and underscore.
files:
A Misc/NEWS.d/next/Library/2022-04-21-19-46-03.gh-issue-91760.zDtv1E.rst
M Doc/library/re.rst
M Doc/whatsnew/3.11.rst
M Lib/re/_parser.py
M Lib/test/test_re.py
diff --git a/Doc/library/re.rst b/Doc/library/re.rst
index 89de9286ace79..3cd9f252fee6f 100644
--- a/Doc/library/re.rst
+++ b/Doc/library/re.rst
@@ -417,6 +417,9 @@ The special characters are:
| | * ``\1`` |
+---------------------------------------+----------------------------------+
+ .. deprecated:: 3.11
+ Group names containing non-ASCII characters in bytes patterns.
+
.. index:: single: (?P=; in regular expressions
``(?P=name)``
@@ -486,6 +489,9 @@ The special characters are:
will match with ``'<user at host.com>'`` as well as ``'user at host.com'``, but
not with ``'<user at host.com'`` nor ``'user at host.com>'``.
+ .. deprecated:: 3.11
+ Group *id* containing anything except ASCII digits.
+
The special sequences consist of ``'\'`` and a character from the list below.
If the ordinary character is not an ASCII digit or an ASCII letter, then the
@@ -995,6 +1001,10 @@ form.
Empty matches for the pattern are replaced when adjacent to a previous
non-empty match.
+ .. deprecated:: 3.11
+ Group *id* containing anything except ASCII digits.
+ Group names containing non-ASCII characters in bytes replacement strings.
+
.. function:: subn(pattern, repl, string, count=0, flags=0)
diff --git a/Doc/whatsnew/3.11.rst b/Doc/whatsnew/3.11.rst
index fdd35ce14317e..1a692f2fe7f60 100644
--- a/Doc/whatsnew/3.11.rst
+++ b/Doc/whatsnew/3.11.rst
@@ -1151,6 +1151,14 @@ Deprecated
(Contributed by Brett Cannon in :issue:`47061` and Victor Stinner in
:gh:`68966`.)
+* More strict rules will be applied now applied for numerical group references
+ and group names in regular expressions in future Python versions.
+ Only sequence of ASCII digits will be now accepted as a numerical reference.
+ The group name in bytes patterns and replacement strings could only
+ contain ASCII letters and digits and underscore.
+ For now, a deprecation warning is raised for such syntax.
+ (Contributed by Serhiy Storchaka in :gh:`91760`.)
+
Removed
=======
diff --git a/Lib/re/_parser.py b/Lib/re/_parser.py
index 933d51589f46c..a393c508d86e5 100644
--- a/Lib/re/_parser.py
+++ b/Lib/re/_parser.py
@@ -287,8 +287,22 @@ def seek(self, index):
self.__next()
def error(self, msg, offset=0):
+ if not self.istext:
+ msg = msg.encode('ascii', 'backslashreplace').decode('ascii')
return error(msg, self.string, self.tell() - offset)
+ def checkgroupname(self, name, offset, nested):
+ if not name.isidentifier():
+ msg = "bad character in group name %r" % name
+ raise self.error(msg, len(name) + offset)
+ if not (self.istext or name.isascii()):
+ import warnings
+ warnings.warn(
+ "bad character in group name %a at position %d" %
+ (name, self.tell() - len(name) - offset),
+ DeprecationWarning, stacklevel=nested + 7
+ )
+
def _class_escape(source, escape):
# handle escape code inside character class
code = ESCAPES.get(escape)
@@ -703,15 +717,11 @@ def _parse(source, state, verbose, nested, first=False):
if sourcematch("<"):
# named group: skip forward to end of name
name = source.getuntil(">", "group name")
- if not name.isidentifier():
- msg = "bad character in group name %r" % name
- raise source.error(msg, len(name) + 1)
+ source.checkgroupname(name, 1, nested)
elif sourcematch("="):
# named backreference
name = source.getuntil(")", "group name")
- if not name.isidentifier():
- msg = "bad character in group name %r" % name
- raise source.error(msg, len(name) + 1)
+ source.checkgroupname(name, 1, nested)
gid = state.groupdict.get(name)
if gid is None:
msg = "unknown group name %r" % name
@@ -773,6 +783,7 @@ def _parse(source, state, verbose, nested, first=False):
# conditional backreference group
condname = source.getuntil(")", "group name")
if condname.isidentifier():
+ source.checkgroupname(condname, 1, nested)
condgroup = state.groupdict.get(condname)
if condgroup is None:
msg = "unknown group name %r" % condname
@@ -795,6 +806,14 @@ def _parse(source, state, verbose, nested, first=False):
state.grouprefpos[condgroup] = (
source.tell() - len(condname) - 1
)
+ if not (condname.isdecimal() and condname.isascii()):
+ import warnings
+ warnings.warn(
+ "bad character in group name %s at position %d" %
+ (repr(condname) if source.istext else ascii(condname),
+ source.tell() - len(condname) - 1),
+ DeprecationWarning, stacklevel=nested + 6
+ )
state.checklookbehindgroup(condgroup, source)
item_yes = _parse(source, state, verbose, nested + 1)
if source.match("|"):
@@ -1000,11 +1019,11 @@ def addgroup(index, pos):
# group
c = this[1]
if c == "g":
- name = ""
if not s.match("<"):
raise s.error("missing <")
name = s.getuntil(">", "group name")
if name.isidentifier():
+ s.checkgroupname(name, 1, -1)
try:
index = groupindex[name]
except KeyError:
@@ -1020,6 +1039,14 @@ def addgroup(index, pos):
if index >= MAXGROUPS:
raise s.error("invalid group reference %d" % index,
len(name) + 1)
+ if not (name.isdecimal() and name.isascii()):
+ import warnings
+ warnings.warn(
+ "bad character in group name %s at position %d" %
+ (repr(name) if s.istext else ascii(name),
+ s.tell() - len(name) - 1),
+ DeprecationWarning, stacklevel=5
+ )
addgroup(index, len(name) + 1)
elif c == "0":
if s.next in OCTDIGITS:
diff --git a/Lib/test/test_re.py b/Lib/test/test_re.py
index a4c2f1f3e4ba3..c1014753802c9 100644
--- a/Lib/test/test_re.py
+++ b/Lib/test/test_re.py
@@ -135,6 +135,7 @@ def test_basic_re_sub(self):
self.assertEqual(re.sub('(?P<a>x)', r'\g<a>\g<1>', 'xx'), 'xxxx')
self.assertEqual(re.sub('(?P<unk>x)', r'\g<unk>\g<unk>', 'xx'), 'xxxx')
self.assertEqual(re.sub('(?P<unk>x)', r'\g<1>\g<1>', 'xx'), 'xxxx')
+ self.assertEqual(re.sub('()x', r'\g<0>\g<0>', 'xx'), 'xxxx')
self.assertEqual(re.sub('a', r'\t\n\v\r\f\a\b', 'a'), '\t\n\v\r\f\a\b')
self.assertEqual(re.sub('a', '\t\n\v\r\f\a\b', 'a'), '\t\n\v\r\f\a\b')
@@ -274,6 +275,21 @@ def test_symbolic_groups_errors(self):
self.checkPatternError('(?P<©>x)', "bad character in group name '©'", 4)
self.checkPatternError('(?P=©)', "bad character in group name '©'", 4)
self.checkPatternError('(?(©)y)', "bad character in group name '©'", 3)
+ with self.assertWarnsRegex(DeprecationWarning,
+ r"bad character in group name '\\xc2\\xb5' "
+ r"at position 4") as w:
+ re.compile(b'(?P<\xc2\xb5>x)')
+ self.assertEqual(w.filename, __file__)
+ with self.assertWarnsRegex(DeprecationWarning,
+ r"bad character in group name '\\xc2\\xb5' "
+ r"at position 4"):
+ self.checkPatternError(b'(?P=\xc2\xb5)',
+ r"unknown group name '\xc2\xb5'", 4)
+ with self.assertWarnsRegex(DeprecationWarning,
+ r"bad character in group name '\\xc2\\xb5' "
+ r"at position 3"):
+ self.checkPatternError(b'(?(\xc2\xb5)y)',
+ r"unknown group name '\xc2\xb5'", 3)
def test_symbolic_refs(self):
self.assertEqual(re.sub('(?P<a>x)|(?P<b>y)', r'\g<b>', 'xx'), '')
@@ -306,12 +322,35 @@ def test_symbolic_refs_errors(self):
re.sub('(?P<a>x)', r'\g<ab>', 'xx')
self.checkTemplateError('(?P<a>x)', r'\g<-1>', 'xx',
"bad character in group name '-1'", 3)
+ with self.assertWarnsRegex(DeprecationWarning,
+ r"bad character in group name '\+1' "
+ r"at position 3") as w:
+ re.sub('(?P<a>x)', r'\g<+1>', 'xx')
+ self.assertEqual(w.filename, __file__)
+ with self.assertWarnsRegex(DeprecationWarning,
+ r"bad character in group name '1_0' "
+ r"at position 3"):
+ re.sub('()'*10, r'\g<1_0>', 'xx')
+ with self.assertWarnsRegex(DeprecationWarning,
+ r"bad character in group name ' 1 ' "
+ r"at position 3"):
+ re.sub('(?P<a>x)', r'\g< 1 >', 'xx')
self.checkTemplateError('(?P<a>x)', r'\g<©>', 'xx',
"bad character in group name '©'", 3)
+ with self.assertWarnsRegex(DeprecationWarning,
+ r"bad character in group name '\\xc2\\xb5' "
+ r"at position 3") as w:
+ with self.assertRaisesRegex(IndexError, "unknown group name '\xc2\xb5'"):
+ re.sub(b'(?P<a>x)', b'\\g<\xc2\xb5>', b'xx')
+ self.assertEqual(w.filename, __file__)
self.checkTemplateError('(?P<a>x)', r'\g<㊀>', 'xx',
"bad character in group name '㊀'", 3)
self.checkTemplateError('(?P<a>x)', r'\g<¹>', 'xx',
"bad character in group name '¹'", 3)
+ with self.assertWarnsRegex(DeprecationWarning,
+ r"bad character in group name '१' "
+ r"at position 3"):
+ re.sub('(?P<a>x)', r'\g<१>', 'xx')
def test_re_subn(self):
self.assertEqual(re.subn("(?i)b+", "x", "bbbb BBBB"), ('x x', 2))
@@ -577,10 +616,27 @@ def test_re_groupref_exists_errors(self):
self.checkPatternError(r'(?P<a>)(?(0)a|b)', 'bad group number', 10)
self.checkPatternError(r'()(?(-1)a|b)',
"bad character in group name '-1'", 5)
+ with self.assertWarnsRegex(DeprecationWarning,
+ r"bad character in group name '\+1' "
+ r"at position 5") as w:
+ re.compile(r'()(?(+1)a|b)')
+ self.assertEqual(w.filename, __file__)
+ with self.assertWarnsRegex(DeprecationWarning,
+ r"bad character in group name '1_0' "
+ r"at position 23"):
+ re.compile(r'()'*10 + r'(?(1_0)a|b)')
+ with self.assertWarnsRegex(DeprecationWarning,
+ r"bad character in group name ' 1 ' "
+ r"at position 5"):
+ re.compile(r'()(?( 1 )a|b)')
self.checkPatternError(r'()(?(㊀)a|b)',
"bad character in group name '㊀'", 5)
self.checkPatternError(r'()(?(¹)a|b)',
"bad character in group name '¹'", 5)
+ with self.assertWarnsRegex(DeprecationWarning,
+ r"bad character in group name '१' "
+ r"at position 5"):
+ re.compile(r'()(?(१)a|b)')
self.checkPatternError(r'()(?(1',
"missing ), unterminated name", 5)
self.checkPatternError(r'()(?(1)a',
diff --git a/Misc/NEWS.d/next/Library/2022-04-21-19-46-03.gh-issue-91760.zDtv1E.rst b/Misc/NEWS.d/next/Library/2022-04-21-19-46-03.gh-issue-91760.zDtv1E.rst
new file mode 100644
index 0000000000000..0bddbbe093144
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2022-04-21-19-46-03.gh-issue-91760.zDtv1E.rst
@@ -0,0 +1,4 @@
+More strict rules will be applied for numerical group references and group
+names in regular expressions. For now, a deprecation warning is emitted for
+group references and group names which will be errors in future Python
+versions.
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