Excuses

ampclient.py

from twisted.internet import reactor, defer
from twisted.internet.protocol import ClientCreator
from twisted.protocols import amp
from ampserver import Sum, Divide


def doMath():
    def menu():
        menu = raw_input('Do you want to divide (d) or add (a)?\n>')
        if menu == 'a':
            print 'You chose for adding'
            askInputAdding()
        elif menu == 'd':
            print 'You chose for dividing'
            askInputDividing()
        else:
            print 'That is not an option'
            menu()

    def askInputAdding():
        a = raw_input('First variable \n>')
        b = raw_input('Second variable \n>')
        try:
            a = int(a)
            b = int(b)
            add(a, b)
        except ValueError:
            print 'Please insert a number'
            askInputAdding()

    def askInputDividing():
        a = raw_input('Numerator \n>')
        b = raw_input('Denumerator \n>')
        try:
            a = int(a)
            b = int(b)
            divide(a, b)
        except ValueError:
            print 'Please insert a number'
            askInput()

    def add(a, b):
        d1 = ClientCreator(reactor, amp.AMP).connectTCP(
            '127.0.0.1', 1234).addCallback(
                lambda p: p.callRemote(Sum, a=a, b=b)).addCallback(
                    lambda result: result['total'])
        d1.addCallback(doneAdding)

    def divide(a, b):
        d2 = ClientCreator(reactor, amp.AMP).connectTCP(
                '127.0.0.1', 1234).addCallback(
                    lambda p: p.callRemote(Divide, numerator=a,
                                   denominator=b)).addErrback(trapZero)
        d2.addCallback(doneDividing)


    def trapZero(result):
        result.trap(ZeroDivisionError)
        print "Divided by zero: returning INF"
        return 1e1000

    def doneAdding(result):
        print 'The answer to the sum is:', result
        menu()

    def doneDividing(result):
        print 'The answer to the sum is', result['result']
        menu()

    menu()

if __name__ == '__main__':
    doMath()
    reactor.run()

ampserver.py

from twisted.protocols import amp

class Sum(amp.Command):
    arguments = [('a', amp.Integer()),
                 ('b', amp.Integer())]
    response = [('total', amp.Integer())]


class Divide(amp.Command):
    arguments = [('numerator', amp.Integer()),
                 ('denominator', amp.Integer())]
    response = [('result', amp.Float())]
    errors = {ZeroDivisionError: 'ZERO_DIVISION'}


class Math(amp.AMP):
    def sum(self, a, b):
        total = a + b
        print 'Did a sum: %d + %d = %d' % (a, b, total)
        return {'total': total}
    Sum.responder(sum)

    def divide(self, numerator, denominator):
        result = float(numerator) / denominator
        print 'Divided: %d / %d = %f' % (numerator, denominator, result)
        return {'result': result}
    Divide.responder(divide)


def main():
    from twisted.internet import reactor
    from twisted.internet.protocol import Factory
    pf = Factory()
    pf.protocol = Math
    reactor.listenTCP(1234, pf)
    print 'started'
    reactor.run()

if __name__ == '__main__':
    main()