from quickfix import *

class MyStringField(quickfix.StringField):
        def __init__(self, data = None)
                if data == None:
                        quickfix.StringField.__init__(self, 6123)
                else:
                        quickfix.StringField.__init__(self, 6123, data)

class MyPriceField(quickfix.DoubleField):
        def __init__(self, data = None)
                if data == None:
                        quickfix.DoubleField.__init__(self, 8756)
                else:
                        quickfix.DoubleField.__init__(self, 8756, data)