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by mianos 1254 days ago
In the 15 years I have been developing in python (and C++ at the same time, daily), I can't remember a single bug I ever had on account of an incorrect type.

I do like the := to save a few lines here and there.

3.10 does seem to run faster but maybe that is my imagination.

I wish more people would focus on writing good python.

3 comments

I live on the opposite planet. basically every bug that I have ever had in python over my 15 years of using it has had to do with a type issue. So the increased use of types and python and ability to express type concepts in python is the thing that I'm most excited about.

it is not necessarily about type mismatch bugs per se, but more like without type information in the code I will misunderstand what kind of structure is passed in to a function, how to decompose it, what members the data has, what functions does it have, how do you spell them correctly, what elements to expect in dictionaries and what kinds of values do they have, and how can I make massive changes to code without knowing all those answers and expect it all to still work.

type annotations are solving a lot of those issues for me nicely, and the number of things that it doesn't solve well is decreasing with each version and the new features they are adding

3.11 runs a bunch faster.
what do you attribute to never finding a bug due to incorrect type? and what is good python vs bad python?
> what do you attribute to never finding a bug due to incorrect type?

If the function/method expects an int, string or complex type and I accidentally call it with the wrong type, resulting in an error, such as "can't add 1 to a string", or "can't access access that method because a string was passed".

>and what is good python vs bad python?

This is kinda of subjective but, for a start, don't just start at the type and do stuff until the bottom like a shell script. This is by far how I see most python scripts. All the other normal things. Don't repeat yourself (in moderation, a few times is OK). Keep it simple.

I guess I meant what do you do to prevent that from happening.
That is my point. I don't have any tools to prevent it from happening. I just don't do it when I write the code. If I have and my code is tested it comes up very quickly.

Us older people tend to keep the whole workflow as simple as possible. That is why I love python. There is very little overhead to just using it.

If you tend to make this mistake a lot it might make sense to add some tooling. I don't need it. If I wanted strict typing I would probably just use C++.

I think you're either misrepresenting reality or stretching the truth.

For example, if you're redefining bug as "bug that made it past testing" that's one thing.

But I don't buy anyone writing Python daily for 15 years hasn't seen the term "TypeError" which is what your previous two comments were implying.

OK, it's 100% likely I saw it, just so rarely I can't remember.

Testing. Over that long time I have used many test frameworks. My normal workflow is to try and exercise all the code I write as I go.

On the other hand I am 100% pedantic about using 'schema' (https://pypi.org/project/schema/) to validate all the types, structure and domains when I read json.

You do get type errors, but you catch them with tests? Type hinting catches them without having to write tests.
So you use some type of testing methodology for your code?