output list reducing each time through loop

[3Pinter]

In getting empty lists as output, and that is something I don't get.

Expected:
[1,2,3,4,5]
[2,3,4,5]
[3,4,5]
[4,5]
[5]

a = [1,2,3,4,5]
output = []

while a:
  output.append(a)
  a.pop(0)

print(output)

I want a seperate 'output'container so I can use that afterwards.