7 Python Code Smells: Olfactory Offenses To Avoid At All Costs

SOLID design principles help avoiding some of these code smells. Watch this video to cleanse yourself ;) : https://youtu.be/pTB30aXS77U.

Don't store monetary amounts in a float! Rounding errors and money don't mix. You should use a decimal type or integer (with the latter getting divided by 100 for display).

First time here. I gotta say: I'm in love with the way you explained why these changes had to be made. They're not just out of "because I say so" great job mate.

This man explains stuff so calmly and I love his accent.

0:00 Intro 1:27 Explaining the example 3:12 Code smell #1: imprecise types 5:52 Code smell #2: duplicate code 7:31 Code smell #3: not using available built-in functions 8:53 Code smell #4: vague identifiers 10:05 Code smell #5: using isinstance to separate behavior 13:40 Code smell #6: using boolean flags to make a method do 2 different things 15:58 Code smell #7: catching and then ignoring exceptions 17:29 Code smell #8 (BONUS): not using custom exceptions 21:30 Final thoughts

SMH I finally learned what enum does. This quickly turned from a code fragrance video into a level up the code video for me.

thanks for doing refactor walk-throughs of implementing concepts, it really does a nice job of reinforcing how it should be after refactor, a lot of tuts just stop at "do this and it will be better" and you going the extra mile is really nice!

I was putting away a large refactoring job for days, but after getting this in my feed I got more confidence in myself seeing these incredibly well explained refactor examples. Managed to finish it in a few hours. Really enjoying your content.

Definitely make this a series! Watching the code be cleaned is wonderful

Honestly, the best python YouTube channel out there for non-beginners! Incredible! Thank you for everything, I'm learning so much from you

Did you notice that the refactoring at 5:52 "Code smell #2: duplicate code" is the exact reverse operation of the refactoring at 13:40 "Code smell #6: using boolean flags to make a method do 2 different things" ? In the first case we combine multiple functions into a single one by adding a parameter. In the second case we remove the parameter and split the function in two. In one case it's better to combine to avoid duplication and in another it's better to split to avoid complicated code. Goes to show programming is not about blindly memorizing language features and rules but there is a sense of 'taste' involved.

I found you from reddit post and I'm glad I did, this video was superb. Amazing work!

There are countless amazing resources to learn python, but as far as going from there and bettering existing skills I don't think any other resource online has given me more practical tips (in one place, with place, easy to digest content) than this channel. Thanks Arjan!

i love how you sped up the parts where you type. usually these videos where people write code in real time get boring quickly because you have to wait for them to type something out. not you however, you're making this really entertaining to watch :D

Thanks for the nice explanations, seeing how these principles get applied onto code examples is a lot more informative and easier to remember than reading about them. Regarding the bonus smell, I'd suggest more emphasis on the usage (you did mention it in the video), when proposing custom exceptions. It's actually good to reuse built-in types as much as possible. Here, custom exceptions were needed, because of the metadata and that there's code somewhere else handling that error.

Great video as always! I think another thing to mention is maybe to think through what responsibilites each class has and/or should have, for example moving the pay() method to the Employee class as you did in the video, maybe move that responsibility back to the Company class with maybe an abstract payment handler that handles it, as it seems kind of weird for an Employee to have the responsibility to pay themselves. Nevertheless, thumbs up and great work!

The custom Exceptions bit was actually really helpful for me! Thank you Arjan!

I absolutely love your videos, randomly found your channel and it is exactly what I was looking for. Exellent content.

This video felt like a senior developer 1 on 1 reviewing my code, it was really helpful, thank you :)

Wonderful video. As a person who only ever writes python code when I'm trying to bodge something together on a raspberry pi its really nice to see how it should be done.