raise not inside exception block

[pyflakes-bot]

Original report by jayvdb (@jayvdb?) on Launchpad:

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raise without any arguments inside an exception block can re-raise the exception.

outside an exception block it causes the following on at least 2.7:

TypeError: exceptions must be old-style classes or derived from BaseException, not NoneType

[pyflakes-bot]

Original comment by jayvdb (@jayvdb?) on Launchpad:

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Fix PR: #57

[pyflakes-bot]

Original comment by bitglue (@bitglue?) on Launchpad:

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This is valid Python code:

def foo():
raise

def bar():
try:
raise Exception()
except:
foo()

As such, a raise outside an except: block isn't an error per se: it depends on the call stack from which its called. Since we can't know that until runtime I don't think it's something Pyflakes can check.