class FirstClass:
    myclass = {}
    
    def __init__(self, ClassList):
        print "FirstClass: I'm alive!"
        self.updateClassList(ClassList)

    def updateClassList(self, ClassList):
        self.myclass = ClassList
        print "FirstClass: classlist updated"

    def hello(self):
        print "FirstClass: Someone said hello!"

    def callSecondClass(self):
        print "FirstClass: Saying hi to SecondClass..."
        self.myclass['SecondClass'].hello()

class SecondClass:
    myclass = {}
    
    def __init__(self, ClassList):
        print "SecondClass: I'm alive!"
        self.updateClassList(ClassList)

    def updateClassList(self, ClassList):
        self.myclass = ClassList
        print "FirstClass: classlist updated"

    def hello(self):
        print "SecondClass: Someone said hello!"

    def callFirstClass(self):
        print "SecondClass: Saying hi to FirstClass..."
        self.myclass['FirstClass'].hello()

'''Main here'''

ClassList = {'FirstClass':None, 'SecondClass':None}

ClassList['FirstClass'] = FirstClass(ClassList)
ClassList['SecondClass'] = SecondClass(ClassList)

for cl in ClassList:
    ClassList[cl].updateClassList(ClassList)

ClassList['FirstClass'].callSecondClass()
ClassList['SecondClass'].callFirstClass()