zero divisoin error

[SabraHashemi]

from below code:

how resolve it?

`def find_corners(poly):
if len(poly) <= 4:
return poly
box = []
box.append(poly[0])

if float(poly[0][1]) - float(poly[1][1]) == 0:
    prev_slope = (float(poly[1][1]) - float(poly[0][1])) * 1000
else:
    prev_slope = (float(poly[1][1]) - float(poly[0][1])) / (float(poly[1][0]) - float(poly[0][0]))

for i in range(1, len(poly)):
    if float(poly[i - 1][1]) - float(poly[i][1]) == 0:
        slope = (float(poly[i][1]) - float(poly[i - 1][1])) * 1000
    else:
        slope = (float(poly[i][1]) - float(poly[i - 1][1])) / (float(poly[i][0]) - float(poly[i - 1][0]))
    if abs(prev_slope - slope) > 2:
        box.append(poly[i - 1])
    prev_slope = slope

box.append(poly[-1])
return np.array(box)`