python2 vs. python3 raise statement
This is specified in the documentation for the raise statement:
You can create an exception and set your own traceback in one step using the
with_traceback()exception method (which returns the same exception instance, with its traceback set to its argument), like so:raise Exception("foo occurred").with_traceback(tracebackobj)
So, in your case, that would be:
raise exc_type(exc_value).with_traceback(tb)