Python: playing with big lists (132M records), checking if item in list

Let's imagine situation when we need to check if item is in list and our list is pretty big. For example, we may have file with hundreds of millions records and we need to develop solution which should be able quickly say if we have specific item in that list or not.

Let's start with naive implementation and then try to improve it iteratively.

This post was inspired by post https://habr.com/ru/post/538358/