import logging
import inspect

tracing_logger = logging.getLogger()
tracing_logger.addHandler(logging.StreamHandler())

def log_info(frame_info):
    tracing_logger.warning("currentThread overridden with None: %s",
                            inspect.getframeinfo(frame_info))

def trace_currentThread(cur_frame, event, arg):
    if event == 'call':
        return trace_currentThread #Trace new scope being entered
    elif event == 'exception':
        return None #Don't need to trace
    else:
        import inspect
        if cur_frame.f_locals.has_key('currentThread'):
            if cur_frame.f_locals['currentThread'] == None:
                log_info(cur_frame)
            elif cur_frame.f_locals.has_key('threading'):
                if cur_frame.f_locals['threading'].currentThread == None:
                    log_info(cur_frame)
            elif cur_frame.f_globals.has_key('currentThread'):
                if cur_frame.f_globals['currentThread'] == None:
                    log_info(cur_frame)
            elif cur_frame.f_globals.has_key('threading'):
                if cur_frame.f_globals['threading'].currentThread == None:
                    log_info(cur_frame)
        return None #Since found error, turn off tracing

def test():
    currentThread = 'A'
    currentThread = None



if __name__ == '__main__':
    import sys
    sys.settrace(trace_currentThread)
    test()