How to solve this problem about ZeroDivisionError: float division by zero?

compactness_list = []
circularity_list = []

for contour in contours:
    perimeter =  cv2.arcLength(contour, True)
    area = cv2.contourArea(contour)

    compactness = (perimeter ** 2) /(area)
    compactness_list.append(compactness)

    circularity = (4 * np.pi * area) / (perimeter)
    circularity_list.append(circularity)

---------------------------------------------------------------------------
ZeroDivisionError                         Traceback (most recent call last)
<ipython-input-165-aa66a2f29568> in <cell line: 4>()
      6     area = cv2.contourArea(contour)
      7 
----> 8     compactness = (perimeter ** 2) / (area)
      9     compactness_list.append(compactness)
     10 

ZeroDivisionError: float division by zero

You can add a try...except block:

for contour in contours:
    perimeter =  cv2.arcLength(contour, True)
    area = cv2.contourArea(contour)

    try:
        compactness = (perimeter ** 2) / area
        circularity = (4 * np.pi * area) / perimeter
    except ZeroDivisionError:
        compactness = 0  # or any other value 
        circularity = 0  # or any other value 

    compactness_list.append(compactness)
    circularity_list.append(circularity)

Or a simple if...else:

for contour in contours:
    perimeter =  cv2.arcLength(contour, True)
    area = cv2.contourArea(contour)

    if area == 0:  # check if area is zero
        compactness = 0  # or any other value
        circularity = 0  # or any other value
    else:
        compactness = (perimeter ** 2) / area
        circularity = (4 * np.pi * area) / perimeter

    compactness_list.append(compactness)
    circularity_list.append(circularity)