a[2] = [3,4]
a[2][1] = 4 # second element of the list a[2]
a[a[2][1]] = a[4] = 5
Remember that in Python index starts from 0.
solved Understanding python list calls
a[2] = [3,4]
a[2][1] = 4 # second element of the list a[2]
a[a[2][1]] = a[4] = 5
Remember that in Python index starts from 0.
solved Understanding python list calls