Detect misuse of except

[Tristan Seligmann]

It would be nice if pyflakes could detect mistakes like this:

       try:
           oldtime = os.path.getmtime(fname)
       except OSError, IOError:
           oldtime = 0

In the general case, it's obviously difficult to tell whether this is an error or not; but I suspect that handling the exception variable name as a binding would give you a "redefinition of Foo" warning in most of the cases where a mistake has been made.

[Jean-Paul Calderone (exarkun)]

Sounds reasonable. At least it would be interesting to run such a check against existing codebases to see what comes up. :)

[Wilfred Hughes (yatc18ks0-9a-ngeefk4xa)]

Pyflakes 0.5.0 does generate the warning "local variable 'IOError' is assigned to but never used", so I believe this has been fixed.

[Tristan Seligmann (mithrandi)]

You only get the unused-local-variable warning if the try/except is in a function. However, it looks like pyflakes does not warn about shadowing builtins, which I thought it did, so my analysis in the description is probably wrong.

[Marcin Cieślak (saperski)]

There is no warning as of pyflakes 0.7.3, marking as fixed

[Marcin Cieślak (saperski)]

er, sorry, misunderstood... should be reopened again