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| author | INADA Naoki <methane@users.noreply.github.com> | 2017-10-13 07:02:23 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2017-10-13 07:02:23 (GMT) |
| commit | b22273ec5d1992b0cbe078b887427ae9977dfb78 (patch) | |
| tree | 513406f0548f326404ff00e67f6a7e9093c78dd2 /Lib/string.py | |
| parent | 925510449984399cf58711843ddfe2e8007c3878 (diff) | |
| download | cpython-b22273ec5d1992b0cbe078b887427ae9977dfb78.zip cpython-b22273ec5d1992b0cbe078b887427ae9977dfb78.tar.gz cpython-b22273ec5d1992b0cbe078b887427ae9977dfb78.tar.bz2 | |
bpo-31672: Fix string.Template accidentally matched non-ASCII identifiers (GH-3872)
Pattern `[a-z]` with `IGNORECASE` flag can match to some non-ASCII characters.
Straightforward solution for this is using `IGNORECASE | ASCII` flag.
But users may subclass `Template` and override only `idpattern`. So we want to
avoid changing `Template.flags`.
So this commit uses local flag `-i` for `idpattern` and change `[a-z]` to `[a-zA-Z]`.
Diffstat (limited to 'Lib/string.py')
| -rw-r--r-- | Lib/string.py | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/Lib/string.py b/Lib/string.py index b46e60c..a3e6d91 100644 --- a/Lib/string.py +++ b/Lib/string.py @@ -79,7 +79,11 @@ class Template(metaclass=_TemplateMetaclass): """A string class for supporting $-substitutions.""" delimiter = '$' - idpattern = r'[_a-z][_a-z0-9]*' + # r'[a-z]' matches to non-ASCII letters when used with IGNORECASE, + # but without ASCII flag. We can't add re.ASCII to flags because of + # backward compatibility. So we use local -i flag and [a-zA-Z] pattern. + # See https://bugs.python.org/issue31672 + idpattern = r'(?-i:[_a-zA-Z][_a-zA-Z0-9]*)' braceidpattern = None flags = _re.IGNORECASE |