"Keyword error on faces" when handing over tuples to f.findAt function

I want to make a set with the help of some python code. The coordinates for the set are stored in the list circle list.

The following I tried:

p = mdb.models['Model-1'].parts['Part-1']
f = p.faces

coordinates_for_faces = tuple()

for i in range(0, len(circleList)):
    tuple_coordinates= (circleList[i].center.x, circleList[i].center.y,0.0)
    coordinates_for_faces = coordinates_for_faces + tuple_coordinates

print("coordinates_for_faces:",  coordinates_for_faces)
faces = f.findAt(*coordinates_for_faces)
p.Set(faces=faces, name='SetOfFibers')

So I stored the coordinates in a tupel. In faces I tried to reference these tupels.

This brings the error "Keyword error on faces" while running the code in python.

I also tried to make a list of tupels and hand over that list of tupels. Attached is the whole code.