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by jraph 1026 days ago
Interesting. 100% of the times I encountered this TypeError, I actually wanted to create the concatenated string. It never caught an actual error.

Now, I guess I'm not against and explicit cast and I can imagine how the error could catch an actual bug. It's painful when the error stops the execution when the string concatenation was intended, but it is not really an issue anymore with the possibility to type check before the execution.

> concatenation of strings is just not the right tool for creating "abc123" from "abc" and 123

Why? This sounds like an opinion to me. String interpolation of formatting features are nice but I find them quite clunky in such simple cases.

Of course when you have to be careful to call str(val), it's arguably as clunky...

1 comments

Of course it’s an opinion. But in my experience, I almost exclusively have some sort of “template” with some parts to fill out, and string interpolation represents this better (in my opinion). This is especially true if the different parts to fill in are of different types.

As I wouldn’t use string concatenation for this purpose, it’s impossible for me to run into a situation where I wanted the concatenated string. (And even if I did, I would be glad for the reminder to change this into an f-string.)

And the bugs that it catches are of the form: I took some user input, expecting it to be a number, but forgot to convert it into one. Then I passed it to a function expecting a number, and it thankfully crashed instead of turning everything else into strings as well.

Maybe this is also a question that informs your view on this: Do you expect "abc" or 123 to be the “variable” part of that expression?

- If "abc" is a literal in the code with 123 coming from a variable, wanting 123 to turn into a string as well is somewhat unterstandable. - However, if 123 is the literal part of the code and "abc" the value of some variable, I would expect to mostly run into this in cases where I am actually doing some math and that the variable is a string just is some accidentally unparsed input.

In what I do, the second case would be more common.