擅长:python、mysql、java
<p>比如:</p>
<pre><code>all_users = [1,2,3,4]
current_user_friends = [1,2]
print list(set(all_users)-set(current_user_friends))
print [user for user in all_users if user not in current_user_friends]
print filter(lambda user: user not in current_user_friends, all_users)
</code></pre>