`re` module not matching `[\s\S]` and equivalents

[michalpokusa]

CircuitPython version

Adafruit CircuitPython 8.2.4 on 2023-08-22; Adafruit Feather ESP32-S2 TFT with ESP32S2

Code/REPL

>>> import re
>>> re.search(r">\S*?<", ">test<") is None
False
>>> re.search(r">\s*?<", "> <") is None
False
>>> re.search(r">[\s\S]*?<", "> test <") is None
True
>>> re.compile(">.*?<", 16).search("> test <") is None
False

Behavior

When searching for \S aka any non-whitespace character, re module finds a match.
Similarly, when searching for \s aka any whitespace character, re module also finds a match.

But, when combining them together, creating a popular any character re module is unable to match.

This pattern is correct, and in theory should be possible to use in CircuitPython, as all the components (\s, \S, sets [], non-greedy *?) are supported.

Similar issue hapens when using \d and \D, \w and \W.

Using .compile() with re.DOTALL which is a literal 16, and with changed patterns ([\s\S] to .) seems to make it possible to match such strings, but still, the issue is present, it is just going around it.

Description

No response

Additional information

Possibly related, but maybe the cause is completely different: #6860

[dhalbert]

Could you test this on a 9.0.0 build to see if the updates from MicroPython fixed it? Thanks.

[michalpokusa]

Could you test this on a 9.0.0 build to see if the updates from MicroPython fixed it? Thanks.

Sure thing. I will test and come back with results.

[michalpokusa]

Well, turns out it does in fact seem to fix the issue. I probably should have tested it myself before posting. Sorry for that.

[dhalbert]

No problem - this is good. We'll want to decide whether to backport the fix to 8.2.x or simply leave your workaround in until 8.x.x has been supplanted by 9.x.x.

[dhalbert]

I will close this, since it's fixed in 9.0.0. We could backport the fix to 8.2.x but having the workaround in the library is good for anyone running a slightly older version, so no need to backport.