Question

So I have a list of numbers in python in a list like this :
[1,89,1221,1919,1920,10210,...] with some thousands of numbers and i want to check if a variabele i is in it.

I do it this way :

if i in mylist:

But is that the fastest way?

Some further specs :

• the list holds no duplicates
• the list only holds integers
• the list can be ordered if that increases performance
• the list can in fact be a set (so no duplicates)
• the list can be any kind of collection

Answer 1

Converting to a set and doing in is the fastest way.

if i in set(mylist):

A set is basically a hash table, and lookups are O(1).