Compare lists in the same dictionary of lists

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]

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/

A solution with list comprehension would be:

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

only_in_a = [x for x in dictionary['a'] if not x in dictionary['b']]
only_in_b = [x for x in dictionary['b'] if not x in dictionary['a']]
in_both = [x for x in dictionary['a'] if x in dictionary['b']]

Note that this is not especially wise in terms of complexity, for larger lists.