Lessons · Python · enumerate (index + value)

Getting the position as well as the item

enumerate walks a list and hands you two things at once: where you are, and what is there.

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What it is for

Position matters constantly in real work. Numbering search results, showing which row of a spreadsheet failed, labeling steps one through five. You need the thing and where it sat.

How to think about it

Ask: do I need the item, or the item and its position? Reach for the position only when you actually use it, otherwise a plain loop is clearer.

Worked example

fruits = ["apple", "pear", "fig"]

Three items. Positions start at 0, not 1.

for i, fruit in enumerate(fruits):

Two names, because enumerate gives two values each turn. i is the position, fruit is the item.

    print(i, fruit)

Prints 0 apple, then 1 pear, then 2 fig.

Your turn

Print each position and item for a list of colors.

colors = ["red", "blue"]
for , color in enumerate(colors):
    print(, color)

The trap

Using one name instead of two, as in for x in enumerate(fruits), gives you the pair stuck together as a tuple rather than the item you wanted.

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