How to split a string into list of combinations

Given a string like /root/2/1/2, how do we construct the following list:

['/root/2/1/2', 'root/2/1', 'root/2', '/root']

>Solution :

A very simple implementation is to split once from the right side on / character iteratively until there is nothing left.

left = '/root/2/1/2'
lst = []
while left:
    lst.append(left)
    left, right = left.rsplit('/', 1)

print(lst)   # ['/root/2/1/2', '/root/2/1', '/root/2', '/root']

Using the walrus operator, we can also write it in a single line (much less readable than the while loop though):

left = '/root/2/1/2'
lst = [left, *(left for _ in range(left.count('/')) if (left:=left.rsplit('/', 1)[0]))]