Matthew Barnett added the comment:
It takes a long time due to excessive backtracking.
The regex implementation on PyPI finishes quickly because it contains some
extra logic to reduce the chances of that happening, but it could be tricky
trying to incorporate that into the existing re module.
Tim Peters added the comment:
Closing this. Since nobody else wants have a go over two decades so far, no
point waiting for that ;-)
--
resolution: invalid - wont fix
stage: - committed/rejected
status: open - closed
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Python tracker
New submission from Taesu Pyo:
// code sampe:
import re
r = (r'(/.*)*X')
s = ''
print re.match(r, s)
print list(re.finditer(r, s))
print re.findall(r, s)
// it does not return or takes long time depends on length of 's'
--
components: Regular Expressions
Tim Peters added the comment:
It will always complete, but may take a very long time - this is one of many
ways to write a regexp that can't match requiring time exponential in the
length of the string. It's not a bug - it's the way Python's kind of regexp
engine works. For detailed
Vajrasky Kok added the comment:
Tim, if you made this ticket as invalid, why don't you close it? Any reason?
--
nosy: +vajrasky
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Python tracker rep...@bugs.python.org
http://bugs.python.org/issue19994
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Tim Peters added the comment:
@vajrasky, I didn't close it just because the usual suspects haven't chimed
in yet. That is, it's a pretty common kind of report, and these usually
attract the same kinds of comments pointing to other regexp implementations.
So leaving it to the regexp person
