Is there a difference between = and IN ( ... )?

Question

SQL

There is a snippet in the code:

if id is not None:
            if type(id) is list:
                q = q.filter(Model.id.in_(id))
            else:
                q = q.filter(Model.id == id)

I'm wondering if the second condition is necessary? Maybe you can get a selection simply through: Just if there is one value in brackets, then it will work just like:
SELECT * FROM TableName WHERE ID IN ( ... )
SELECT * FROM TableName WHERE ID IN (42)

Answer 1

There was a similar question on stackoverflow. They concluded that there was no difference.
The query EXPLAIN is the same in both cases
https://stackoverflow.com/questions/9926433/mysql-...