omero.gateway assert_re decorator raises TypeError during exception checking

[jmuhlich]

omero-py/src/omero/gateway/__init__.py

Line 7927 in 05d5241

def __init__(self, onPrepareFailureReturnNone=True, ignoreExceptions=None):

omero-py/src/omero/gateway/__init__.py

Line 7958 in 05d5241

except ctx.ignoreExceptions:

The default value of ignoreExceptions in the assert_re decorator initializer is None but except None is invalid, raising a TypeError:

TypeError: catching classes that do not inherit from BaseException is not allowed

Exception chaining does retain the original exception and traceback but it's confusing to see this extra unrelated error.

except None was allowed in Python 2, where the argument to except could be anything and non-exception types would simply never match any actual raised exception. The no-match equivalent for Python 3 is an empty tuple, so I think the default arg for ignoreExceptions should be changed to ().

[jmuhlich]

Sorry, duplicate of #356 and #308 ! But I guess I did add something in the form of a suggested fix... :)