Python: what is the difference between (1,2,3) and [1,2,3], and when should I use each?

Question

In many places, (1,2,3) (a tuple) and [1,2,3] (a list) can be used interchangeably.

When should I use one or the other, and why?

Answer 1

• A tuple might represent a key in dictionary, because it's immutable.
• Use lists if you have a collection of data that doesn't need random access.