AppEngine debugging tip

As i explained in my last blog post, GAE does some very weird stuff with stdout, making it very difficult to print information from arbitrary points of code. For example if you invoked the Pdb(stdout=sys.__stdout__) i couldn't print on my screen from a POST request. I have finally found a fix for that annoyance, you hack sys.stdout:

def set_trace():

    import pdb, sys

    sys.stdout = sys.__stdout__

    sys.stdin = sys.__stdin__

    debugger = pdb.Pdb()

    debugger.set_trace(sys._getframe().f_back)