# grows the list by list[len(list[n])+1][len(list[n][n])+1]
pythonlist = [[1], [2]]

for index, i in enumerate(pythonlist):
    pythonlist[index].append(0)
pythonlist.append([])
for i in range(len(pythonlist)):
    pythonlist[-1].append(0)


# Shrink
print(pythonlist)

# shrinks the list by list[len(list[n])-1][len(list[n][n])-1]
for index, i in enumerate(pythonlist):
    pythonlist[index].pop()
pythonlist.pop()

print(pythonlist)