def partition(L):
    j = 0

    for i in range(1, len(L)):
        val = L[i]
        k = i

        while k > j and val < 0:
            L[k] = L[k - 1]
            k -= 1

            if j == k:
                j += 1

        L[k] = val

L = [9, 2, -3, 1, 0, 0, -7, -6, 3, -5, 2]
partition(L)

# result: [-3, -7, -6, -5, 9, 2, 1, 0, 0, 3, 2]