recursion: find all ways to add elements in an list to get to n in python

Question

For example,

given a list [1,2,3,4] and `n=4`

my output should be

7:
1+1+1+1=4
1+1+2=4
1+2+1=4
1+3=4
2+2=4
2+1+1=4
3+1=4