InsertionSort in Python

A = [2,1,5,3,7,99,8]

def insertionsort(A):
    for j in range(1,len(A)):
        key = A[j]
        i = j - 1
        while i != -1 and key < A[i]:
            A[j]=A[i]
            i = i-1
    A[i+1] = key

insertionsort(A)
print(A)