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The Friday Loop

Ridiculous Ways to Define Functions in Python | Issue #56

Published about 2 months ago • 2 min read

Hi there,

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We all use def to define functions in Python. But did you know there are at least 7 other ways to do it? Some of them are useful. Some are questionable. And the last one is so ridiculous, it might crash your interpreter.
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In this week’s video, I walk through each method, explain how it works, why you should use it (or not), and what it teaches us about how Python works under the hood.
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This was a really interesting topic to explore. I learned a lot from it and I hope you will too.

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Happy coding!

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Cheers,

Arjan

# News

It’s My Birthday Week! 🎉

That’s right: I’m officially getting deprecated… but still fully functional! On June 8th, I’m turning 48, and to celebrate another year under the sun, I’m giving you a special gift: 20% off all ArjanCodes courses (excluding the Professional version).

It’s the perfect performance boost for your coding skills.

To claim your 20% discount, use coupon code BIRTHDAY2025 at checkout. This offer is available until June 8th at midnight!

Debugging f-strings Is Fun

Here’s something weird I came across this week. Your str(obj) call works just fine… but plug that same object into an f-string and boom — you get a TypeError.

Turns out, f-strings don't use str() under the hood — they use format(). And in some edge cases (like with proxy objects or sandboxed environments), that subtle difference matters.

Brandon Chinn wrote a great deep dive on this exact problem. Check it out here.

It’s a great reminder that Python is usually friendly, until it’s not.

# Community

How Do You Learn Software Architecture?

This week someone asked a great question in my Discord server: “I can write code, but how do I get better at designing it?”

That kicked off a really thoughtful thread about learning architecture step by step, dealing with anxiety while coding, and figuring out how to make your code easier to change later. A few great book recommendations came up too.

If you ever feel stuck trying to structure your code or scale your skills, you’re not alone, and the Discord is a great place to talk about it.

👉 Join the community now to read the discussion and share your thoughts.

Do you enjoy my content on YouTube and would you like to dive in deeper?

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The Friday Loop

by ArjanCodes

Every Friday, you'll get a recap of the most important and exciting Python and coding news. The Friday Loop also keeps everyone posted on new ArjanCodes courses and any limited offers coming up.

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