I'm all in favor of the walrus operator for the for loop, but the first example given to justify it is code I'd never write. The first if does a return, so there is no need for the else: and indentation. I'm sure there are other code examples that would justify it, but this one is unconvincing.
What's Coming in Python 3.8
31–40 of 558 posts
Re: What's Coming in Python 3.8
#32Walrus operator looks like a great addition, not too much syntax sugar for a common pattern. Why were folks arguing about it?
Change aversion.
Re: What's Coming in Python 3.8
#33Speaking as someone who has written Python code almost every day for the last 16 years of my life: I'm not happy about this. Some of this stuff seems to me like it's opening the doors for some antipatterns that I'm consistently frustrated about when working with Perl code (that I didn't write myself). I had always been quite happy about the fact that Python didn't have language features to blur the lines between what…
F-strings have appeared 2 versions ago. All in all, the feedback we have has been overwhelmingly positive, including on maintenance and readability.
...but every addition to make them more powerful and feature-rich is one more step in the direction of blurring the lines between what's code and what isn't, since more and more things that are supposed to be code will be expressed in ways that aren't code at all but fed to an interpreter inside the interpreter. And with every release, the language specification that I'm having to hold in my head when dealing with other people's code grows more and more complex while the cost-benefit calculation around the additional complexity shows diminishing returns.
It kind of goes to the question: When is a language "finished"?
Re: What's Coming in Python 3.8
#34Earlier quoted context omitted.
F-strings have appeared 2 versions ago. All in all, the feedback we have has been overwhelmingly positive, including on maintenance and readability.
I love f-strings. I just wish tools like pylint would shut up when I pass f-strings to the logging module. I as the developer understand and accept the extra nanosecond of processor time to parse the string that might not be logged anywhere!
Disable it in pylintrc. Pylint is unusable without a good config file anyway.
Re: What's Coming in Python 3.8
#35Speaking as someone who has written Python code almost every day for the last 16 years of my life: I'm not happy about this. Some of this stuff seems to me like it's opening the doors for some antipatterns that I'm consistently frustrated about when working with Perl code (that I didn't write myself). I had always been quite happy about the fact that Python didn't have language features to blur the lines between what…
Do you have an example of bad code you'd expect people to use assignment expressions and f-strings for?
I don't think I've come across any f-string abuse in the wild so far, and my tentative impression is that there's a few patterns that are improved by assignment expressions and little temptation to use them for evil.
It helps that the iteration protocol is deeply ingrained in the language. A lot of code that could use assignment expressions in principle already has a for loop as the equally compact established idiom.
Re: What's Coming in Python 3.8
#36Python looks more and more foreign with each release. I'm not sure what happened after 3.3 but it seems like the whole philosophy of "pythonic", emphasizing simplicity, readability and "only one straightforward way to do it" is rapidly disappearing.
“I've come up with a set of rules that describe our reactions to technologies: 1. Anything that is in the world when you’re born is normal and ordinary and is just a natural part of the way the world works. 2. Anything that's invented between when you’re fifteen and thirty-five is new and exciting and revolutionary and you can probably get a career in it. 3. Anything invented after you're thirty-five is against the n…
Does that mean someone born in 2008 will think C++ is simple and elegant?
Re: What's Coming in Python 3.8
#37Walrus operator looks like a great addition, not too much syntax sugar for a common pattern. Why were folks arguing about it?
It's not that common. There's 1 place where its useful imo (comprehensions to avoid duplicate calls), but even that can be handled case by case, and it certainly isn't a common thing.
It's extremely common.
I've had to use a workaround for that every time I've tested a regular expression match that I wanted to process for example. Also problematic in comprehensions...
Re: What's Coming in Python 3.8
#38Walrus operator looks like a great addition, not too much syntax sugar for a common pattern. Why were folks arguing about it?
Because it goes against 20 years of the principles behind the language.
Actually it doesn't violate any of the principles behind the language. It could have been there from day one, like tons of others things added later and now totally loved.
I should know, I've worked with Python for 22 years...
Re: What's Coming in Python 3.8
#39Do parsers of previous pythons emit warnings: "this feature is not available in pythons 3.3 3.4 3.5 etc" ?
Re: What's Coming in Python 3.8
#40I noticed some changes to pickle; do people still use pickle for Real Work?
Potential vulnerabilities aside, I got bitten by some migration issue back in the 2.2 to 2.4 transition where some built-in types changed how they did their __setstate__ and __getstate__ (iirc) and that caused objects picked under 2.4 to not unpickle correctly under 2.2 or something like that. After that I never wanted to use pickle in production again.