import pyutilib.workflow

class TaskA(pyutilib.workflow.Task):

    def __init__(self, *args, **kwds):
        """Constructor."""
        pyutilib.workflow.Task.__init__(self, *args, **kwds)
        self.inputs.declare('x')
        self.inputs.declare('y')
        self.outputs.declare('z')

    def execute(self):
        """Compute the sum of the inputs."""
        self.z = self.x + self.y

class TaskC(pyutilib.workflow.Task):

    def __init__(self, *args, **kwds):
        """Constructor."""
        pyutilib.workflow.Task.__init__(self, *args, **kwds)
        self.inputs.declare('X')
        self.inputs.declare('y')
        self.outputs.declare('W')
        self.outputs.declare('Z')

    def execute(self):
        """Compute the sum of the inputs."""
        self.W = self.X+self.y
        self.Z = 2*self.W

# @ex:
A = TaskA()
C = TaskC()
A.inputs.x = C.outputs.Z

w1 = pyutilib.workflow.Workflow()
w1.add(A)

AA = TaskA()
AA.inputs.x = w1.outputs.W
AA.inputs.y = w1.outputs.z

w2 = pyutilib.workflow.Workflow()
w2.add(AA)

print(w2(X=1, y=3))
# @:ex