The Most Misunderstood Python Functions (And How to Use Them Correctly)

Avoid common Python mistakes! Learn how zip(), defaultdict(), enumerate(), and more really work-so you can debug smarter and code better.

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Ever used a Python function thinking, “Yeah, I got this,” only to be hit with an unexpected error or — worse — silence? Been there. Python is praised for its readability, but some functions? They’re sneaky. Let’s break down the most commonly misunderstood ones so you can avoid those “Why is this happening?!” moments.

1. zip() — Pairs, Not Perfection

You might think zip() is about compression. Nope. It’s about pairing up iterables. Sounds simple, but watch this:

pairs = zip([1, 2, 3], ['a', 'b'])
print(list(pairs))

Output:

[(1, 'a'), (2, 'b')]

Where’s (3, ‘c’)? Exactly. zip() stops at the shortest iterable. I learned this the hard way when half my dataset disappeared. If you need all elements, use itertools.zip_longest() instead.

2. defaultdict() — A Lifesaver (Until It’s Not)

A defaultdict auto-creates default values. Sounds great, right? Until it hides bugs.

from collections import defaultdict
d =…