There is an issue with condition.wait() ignoring SIGINT https://bugs.python.org/issue8844

It has been fixed on Python3, but was not backported to Python2.7. This can cause clients to hang on SIGINT if there are unfinished streaming calls.

Condition.wait(timeout) does not have this problem, but looking at the implementation, it does a 1-5 ms poll on the lock in Python (with the GIL), so I don't think its justified doing that as part of the main event loop.