Python: Passing a class name as a parameter to a function?

Question

class TestSpeedRetrieval(webapp.RequestHandler):   """   Test retrieval times of various important records in the BigTable database    """   def get(self):       commandValidated = True        beginTime = time()       itemList = Subscriber.all().fetch(1000)         for item in itemList:            pass        endTime = time()       self.response.out.write("<br/>Subscribers count=" + str(len(itemList)) +             " Duration=" + duration(beginTime,endTime))  

How can I turn the above into a function where I pass the name of the class? In the above example, Subscriber (in the Subscriber.all().fetch statement) is a class name, which is how you define data tables in Google BigTable with Python.

I want to do something like this:

       TestRetrievalOfClass(Subscriber)   or     TestRetrievalOfClass("Subscriber")   

Thanks, Neal Walters

Answer 1

class TestSpeedRetrieval(webapp.RequestHandler):   """   Test retrieval times of various important records in the BigTable database    """   def __init__(self, cls):       self.cls = cls    def get(self):       commandValidated = True        beginTime = time()       itemList = self.cls.all().fetch(1000)         for item in itemList:            pass        endTime = time()       self.response.out.write("<br/>%s count=%d Duration=%s" % (self.cls.__name__, len(itemList), duration(beginTime,endTime))  TestRetrievalOfClass(Subscriber)   

Answer 2

If you pass the class object directly, as in your code between "like this" and "or", you can get its name as the __name__ attribute.

Starting with the name (as in your code after "or") makes it REALLY hard (and not unambiguous) to retrieve the class object unless you have some indication about where the class object may be contained -- so why not pass the class object instead?!