Compare lists in the same dictionary of lists

Question

In resume, I have two keys in the same dictionary where each one has their corresponding lists.

I try to compare both list to check common and differential elements. It means that the output I will count how many elements are identical or present in only one key's list.

from the beginning I am inserting the elements using the files as arguments and they are read in the function

def shared(list):
        dict_shared = {}
        for i in list:
                infile = open(i, 'r')
                if i not in dict_shared:
                        dict_shared[i] = []

                for line in infile:
                        dict_shared[spacer].append(record.id)

        return dict_shared

Now I am stuck trying to find a way to compare the lists created and present in the dictionary.

dict = {a:[1,2,3,4,5], b:[2,3,4,6]}

My intention is to compare the lists in order to have the lines shared between two texts.

a: [1,5]
b: [6]
a-b: [2,3,4]

From now I can't find a way to solve this. Any suggestion?

Answer 1

You could use set:

d = {'a':[1,2,3,4,5], 'b':[2,3,4,6]}
print(list(set(d['a'])-set(d['b'])))
print(list(set(d['b'])-set(d['a'])))
print(list(set(d['b'])&set(d['a'])))

result:

[1, 5]
[6]
[2, 3, 4]

Answer 2

you can do that by utilising python inbuilt functions like union, difference, intersection. Note: These are for sets, you can convert a list to set by

1stset = set(a)

example:

print(1stset.difference(2ndset))

print(1stset.intersection(2ndset))

print(1stset.union(2ndset))

you can refer the following links for more information

https://www.geeksforgeeks.org/python-intersection-two-lists/

https://www.geeksforgeeks.org/python-union-two-lists/

https://www.geeksforgeeks.org/python-difference-two-lists/