Find maximum value of Sum( i*arr[i]) with only rotations on given array allowed

def maxSum(arr):

arrSum = 0

currVal = 0

n = len(arr)

for i in range(0, n):

arrSum = arrSum + arr[i]

currVal = currVal + (i*arr[i])

maxVal = currVal

for j in range(1, n):

currVal = currVal + arrSum-n*arr[n-j]

if currVal > maxVal:

maxVal = currVal

return maxVal

if __name__ == '__main__':

arr = [10, 1, 2, 3, 4, 5, 6, 7, 8, 9]

print ("Max sum is: ", maxSum(arr))