Enumerate Intermediate Python Tutorial part 7

Welcome to part 7 of the intermediate Python programming tutorial series. In this part, we're going to talk about the built-in function: enumerate.

A somewhat common task might be to attempt to attach an index value, or some other unique value to list items. Maybe something like this looks vaguely familiar:

example = ['left','right','up','down']
for i in range(len(example)):
    print(i, example[i])

0 left
1 right
2 up
3 down

Instead, you can do:

for i,j in enumerate(example):
    print(i,j)

The enumerate function returns a tuple containing the count, and then the actual value from the iterable.

That iterable can be a dict:

example_dict = {'left':'<','right':'>','up':'^','down':'v',}
[print(i,j) for i,j in enumerate(example_dict)]

You can even create new dicts with a list and enumerate:

new_dict = dict(enumerate(example))
print(new_dict)

The last example is one I have used to store objects, using enumerate to make a sort of unique id for them.

That's all for enumerate! In the next tutorial, we're going to cover the zip function.

The next tutorial: Python's Zip function