solution required in python

Task 2 Write a function, "subsequences" that returns all the subsequences in a list of a string (which the function takes as an argument). For example, subsequences of "abc" might return ["abc", "ab", "bc","ac","a", "b","c",""). Note the empty string, which is also a valid subsequence. This problem lends itself to an elegant recursive decomposition. Take the first letter of the word. We can form one set of subsequences that include that letter, and another set of subsequences that exclude that letter, and those two sets completely cover the set of possible subsequences. Sample run: Enter string: abc Subsequences of abc ["abc","ab","bc","c","a","b","c",""]