When being invoked asynchronously, the API client now handles exceptions and passes them to the given callback. For example:
python
def my_callback(response):
if type(response) is mparticle.rest.ApiException:
print 'An error occurred: ' + str(response)
else:
successful uploads will yield an HTTP 202 response and no body
print response
api_instance.upload_events(batch, my_callback)