Suppose I have the following command (using Python and Qiskit):
a = reduce(lambda x,y: x.compose(y,c),circli, qcla)
(qcla is an initializer)
Here, compose is an internal qiskit function, x and y are elements of the list circli (iterable). I'm wondering is it possible for me to add another iterable in this reduce function? Here, c itself in (y,c) represents a coordinate, such as [2,3], and I'm hoping to have it updated as well. Can I create another list containing all the possible c's and add it as another iterable? Thanks!
It is possible to reduce a list (iterable) of pairs and also to create a pair at the end. For the first one you need the zip function, for the latter one you need to modify the lambda function to return a tuple. For example:
a, x_sum = reduce(lambda x,y: (x[0].compose(y[0], y[1]), x[1][0]+y[1][0]), zip(circli, cs), (qcla, 0))
I use the name cs for the list of c values here.
zip creates pairs of circli and cs items and you can go through the pairs. In this case I get the sum of the x coordinates of c values as the result as well.
If the values in cs is the constant c in your example (cs = [c]*len(circli)) , the a in the result will be the same as in your example.