Stripe not Throwing Charging Error in Python

I am using the stripe library in Python for credit card charging. I use the customerID for purposes of charging rather than the token as I want to re-use the card without asking for it each time. The success process works just fine, however, if I create an error condition the "except" is never thrown. I am testing the failure state by using an invalid customer ID.

The server log shows the following error: "InvalidRequestError: Request req_8949iJfEmeX39p: No such customer: 22" but again this is not handled in try/except.

class ChargeCustomerCard(webapp2.RequestHandler):
def post(self):
    stripe.api_key = stripeApiKey
    customerID = self.request.get("cust")
    amount = self.request.get("amt")

    try:
        charge = stripe.Charge.create(amount=int(amount),currency="usd",customer=customerID,description=customerID)
    except stripe.error.CardError, e:
        output = {"result":e}
    else:
        output = {"result":"1"}

    self.response.out.write(json.dumps(output))