min1 = score_arr should be changed to min1 = score_arr[i].
min1 = score_arr is setting min1 to the whole list, so the next iteration fails on the line if score_arr[i] < min1 since score_arr[i] is a float and min1 is now a list (as indicated by the error message).
But, a better way to find the minimum would be min(score_arr) (just like you used max on the second line).
3
solved Error : TypeError: unorderable types: float() < list() [closed]