Difference between lists in Python

Question

Is there any way to detect distinction after two lists comparison, if second list is more important?

List1 items: 1 2 3 4
List2 items: 1 2   4

Expected result should be: remove 3

List1 items: 1 2 3 4 
List2 items: 1 2 3 4 5

Expected result should be: no further changes

List1 items: 1 2 3 4 5
List2 items: 1 2 3 4 6

Expected result should be: remove 5

Sure, I tried intersect and something like: [x for x in platform_normal_array if x not in s] — DzLL, Feb 28 '16 at 17:26
Also, what should be the result if the order of items is different between the lists? This question is not clearly specified yet. — Tim Pietzcker, Feb 28 '16 at 17:37
order of items is not important in my case. I just want to remove items from 1st list, which are not present in 2nd list — DzLL, Feb 28 '16 at 17:45

score 1 · Answer 1 · answered Feb 28 '16 at 17:48

1

set(list1) - set(list2) will return a set of missing items.

answered Feb 28 '16 at 17:48

L3viathan

score 0 · Accepted Answer · answered Feb 28 '16 at 17:53

"I just want to remove items from 1st list, which are not present in 2nd list"

"Expected result should be: remove 3"

In [11]: list1 = {1, 2, 3, 4}
In [12]: list2 = {1, 2, 4}
In [13]: set.difference(list1, list2)
Out[13]: {3}

"Expected result should be: no further changes"

In [14]: list1 = {1, 2, 3, 4}
In [15]: list2 = {1, 2, 3, 4, 5}
In [16]: set.difference(list1, list2)
Out[16]: set()

"Expected result should be: remove 5"

In [17]: list1 = {1, 2, 3, 4, 5}
In [18]: list2 = {1, 2, 3, 4, 6}
In [19]: set.difference(list1, list2)
Out[19]: {5}

2 Answers2