How to generate substrings of a dot-separated string?

I am struggling to generate a list of substrings from a given list of strings.

I have a list of domains –

domains = ["abc.pqr.com", "pqr.yum.abc.com"]

Now, for each domain in the list I want to generate subdomains.

For example the subdomains of domain "abc.pqr.com" would be

["pqr.com", "abc.pqr.com"]

Also, for domain "pqr.yum.abc.com" the subdomains would be

["yum.abc.com", "pqr.yum.abc.com", "abc.com"]

So the out put of the method would be –

["yum.abc.com", "pqr.yum.abc.com", "abc.com", "pqr.com", "abc.pqr.com"]

>Solution :

First you have to iterate on elements then split your element by the ‘.’ seperator. After that in order to keep the ‘com’ element intact, we iterate on the range – 1. After creating every alternative, we join the result again with the seperator "."

domains = ["abc.pqr.com", "pqr.yum.abc.com"]
domains_new = []
for d in domains:
    liste = d.split(".")
    for i in range(len(liste)-1):
        domains_new.append(liste[i:])
domains_new = [".".join(ele) for ele in domains_new]
domains_new

output:

['abc.pqr.com', 'pqr.com', 'pqr.yum.abc.com', 'yum.abc.com', 'abc.com']