[Python] UnboundLocalError in Python exception block [duplicate]

My code:

from re import match

def main():
try:
raise Exception("hello world")
except Exception as exception:
match = match("^(.+?)$", str(exception))

print(match)

if __name__ == "__main__":
main()


The error message:

Traceback (most recent call last):
File ".../test.py", line 5, in main
raise Exception("hello world")
Exception: hello world

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File ".../test.py", line 12, in <module>
main()
~~~~^^
File ".../test.py", line 7, in main
match = match("^(.+?)$", str(exception))
^^^^^
UnboundLocalError: cannot access local variable 'match' where it is not associated with a value


Moving the code out of main doesn't causes this problem though:

from re import match

try:
raise Exception("hello world")
except Exception as exception:
match = match("^(.+?)$", str(exception))

print(match)


Output:

<re.Match object; span=(0, 11), match='hello world'>


What is going on here?

The question was closed and it redirected me to a problem which uses global variable while mine doesn't. Is importing a function also similar to global variables?

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