The OpenCV documentation for cv.houghcircles() includes an optional output vector array, denoted "circles."
cv.HoughCircles( image, method, dp, minDist[, circles[, param1[, param2[, minRadius[, maxRadius]]]]] ) -> circles
In no python example have I seen any use of this parameter. And, although the nested brackets seem to require the use of the output vector parameter in order to use the following parameters, again, I've never seen it used. I do see "circles" used as the output array such that the returned output of the method is assigned to "circles."
circles = cv2.houghcircles(img, method, dp, minDist, param1, param2, minrad, maxrad)
Is the output vector passed as a parameter into the call only used in C++, or, is there a context in python in which one would pass the output vector into the function call as it is described in the documentation?
(Also, am I correctly interpreting the nested brackets to mean that each nested level of optional parameter requires the preceding level?)