server

client.py

from twisted.internet import reactor  
from twisted.internet.protocol import Protocol, ClientFactory
from twisted.protocols import amp

class ChangeCurrency(amp.Command):
    arguments = [('newPrice', amp.Integer())]

class MarketProtocol(amp.AMP):
    def __init__(self, price):
        self.price = price
        
    def connectionMade(self):
        self.callRemote(ChangePrice, newPrice=price) 
        print 'connection made'

    def changeCurrency(self):
        self.factory.currency = price 

class Factory(ClientFactory):
    def __init__(self, price):
        self.price = price
        self.currency = 0

    def buildProtocol(self, addr):
        return MarketProtocol(self.price)

def printCurrency():
    print factory.currency

def main(price):
    from twisted.internet import reactor
    print 'installed'
    factory = Factory(price)
    print 'initializing factory'
    reactor.connectTCP("86.85.138.215", 45000, factory) 
    print 'connecting'
    reactor.run()
    print 'reactor done running'

if __name__=="__main__":main(10)

error

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/twisted/python/log.py", line 84, in callWithLogger
    return callWithContext({"system": lp}, func, *args, **kw)
  File "/usr/lib/python2.7/dist-packages/twisted/python/log.py", line 69, in callWithContext
    return context.call({ILogContext: newCtx}, func, *args, **kw)
  File "/usr/lib/python2.7/dist-packages/twisted/python/context.py", line 118, in callWithContext
    return self.currentContext().callWithContext(ctx, func, *args, **kw)
  File "/usr/lib/python2.7/dist-packages/twisted/python/context.py", line 81, in callWithContext
    return func(*args,**kw)
--- <exception caught here> ---
  File "/usr/lib/python2.7/dist-packages/twisted/internet/posixbase.py", line 591, in _doReadOrWrite
    why = selectable.doWrite()
  File "/usr/lib/python2.7/dist-packages/twisted/internet/tcp.py", line 419, in doConnect
    self._connectDone()
  File "/usr/lib/python2.7/dist-packages/twisted/internet/tcp.py", line 427, in _connectDone
    self.protocol.makeConnection(self)
  File "/usr/lib/python2.7/dist-packages/twisted/protocols/amp.py", line 2295, in makeConnection
    BinaryBoxProtocol.makeConnection(self, transport)
  File "/usr/lib/python2.7/dist-packages/twisted/protocols/amp.py", line 2042, in makeConnection
    self.connectionMade()
  File "client.py", line 13, in connectionMade
    self.callRemote(ChangePrice, newPrice=price)
exceptions.NameError: global name 'ChangePrice' is not defined