I have two lists:

l1: 38510 entries
l2: 6384 entries

I want to extract only values, which are present in both lists.

So far that was my approach:

```
equals = []

for quote in l2:
   for quote2 in l1:
      if quote == quote2:
         equals.append(quote)

len(equals)) = 4999
len(set(equals))) = 4452

```

First of all, I have the feeling this approach is pretty inefficient, because I am checking every value in l1 several times ..

Furthermore, it seems that I get still duplicates. Is this due to the inner-loop for l1?

Thank you!!