Finding an index in Python

Question

How do I find the index of an item from a list?

For example, I have a list - ["ace, "tot", "pen"] and I need to find the index of pen from the list which should be (2)

Answer 1

You can find the index in the following way-

>>> ["ace", "tot", "pen"].index("pen")
2

Note that while this is perhaps the cleanest way to answer the question as asked, index is a rather weak component of the list API, and I can't remember the last time I used it in anger. It's been pointed out to me in the comments that because this answer is heavily referenced, it should be made more complete.