The dumps param in simplejson.dumps is often helpful, but sometimes you want to quickly pass in multiple default actions. This should help.

compose_defaults

def compose_defaults(*defaults):
    '''I got annoyed that simplejson.dumps doesn't let you pass multiple
    defaults. So here's this.'''
    def new_default(obj):
        for default in defaults:
            try:
                return default(obj)
            except:
                pass
        raise TypeError("no default functions succeeded")
    return new_default