def subshift(L, start, end, insert_at):
    temp = L[start:end]
L = L[:start] + L[end:]
return L[:insert_at] + temp + L[insert_at:]
print(subshift(['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'], 2, 5, 4))
Fastest way to reposition sublist in python