A slightly extended version prevents only allowed exceptions:

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class ignore_error(object):
    def __init__(self, *args):
        self.tolerable = args

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        return exc_type in self.tolerable if len(self.tolerable) else True


with ignore_error(NameError, poser.error):
    actor = poser.Scene().Actor("not existing actor")

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(The construct is called "Context Manager", by the way).

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