Python 3 UnboundLocalError not detected when variable referenced after shadowed by exception variable
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python3
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Description
For
def a():
e = 1
try:
raise RuntimeError('forced error')
except Exception as e:
print(e)
print(e)
a()
In both Python 2 and 3, exception variable e shadows the local variable e, and is not being reported.
In python3, e is unbound after the exception block, and a UnboundLocalError occurs when the local variable e is referenced because it was disappeared.
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Research direction
Start by running the supplied Python example through pyflakes and trace how exception-variable handling affects the later reference. No file or test is named; done means the post-exception reference is reported, with a regression test covering this Python 3 behavior.
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Assessment
- Tech stack
- python
- Domain
- tooling
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100