def compute(self):

        self.setInitialValue()
        self.partialResult = self.initialValue
        self.elementResult = None

        for element in self.get_input('InputList'):
            self.element = element
            self.operation()

        self.set_output('Result', self.partialResult)
Arguments:
dataset/ETHPy150Open VisTrails/VisTrails/vistrails/packages/controlflow/fold.py/Fold.compute--crossover with--dataset/ETHPy150Open django/django/django/db/models/expressions.py/F.__init__