---
title: "In the Know"
url: https://daily.dev/posts/in-the-know-5pau59amv
source_url: https://thedailywtf.com/articles/in-the-know
type: article
source: "The Daily WTF"
published: 2026-05-21T11:05:01.029Z
updated: 2026-05-21T11:05:18.030Z
tags: ["python"]
reading_time: 3
upvotes: 0
comments: 0
language: en
---

> ## Documentation Index
> Fetch the complete documentation index at: https://daily.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# In the Know

**[The Daily WTF](https://daily.dev/sources/thedailywtf)** · 3 min read · 0 upvotes · 0 comments

## Summary

A Python developer's co-worker wrote a needless `key_exists` function that reimplements Python's built-in `in` operator using try/except, then inconsistently used both the custom function and the correct idiom in the same 48-line script. The full script merges YAML configuration files but is riddled with poor practices, including an unused list variable that would cause a NameError at runtime.

## Full article

daily.dev links to this article rather than hosting it. Read it at the original source: <https://thedailywtf.com/articles/in-the-know>

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- [Brillant Python Programmers](https://daily.dev/posts/brillant-python-programmers-xaqe6dj7t) · The Daily WTF · 1 upvotes · 0 comments

---

Tags: [#python](https://daily.dev/tags/python)

[View this post on daily.dev](https://daily.dev/posts/in-the-know-5pau59amv)