4 ms·

There is another universe where Python 3 only fixed the unicode strings, and the transition was a huge success and over in a couple of years. The print() funct

There is another universe where Python 3 only fixed the unicode strings, and the transition was a huge success and over in a couple of years. The print() function was absolutely not worth all the carnage it caused. They could have just kept the print statement around and introduced a printing function with a different name, for example. The fact that they removed syntax for Python 3 meant that all kinds of scientific computing code had to be transitioned even if it didn't use any strings!

chaosite 4y ago
Wait, if it didn't use any strings, then it didn't use the print statement either, right?
- zarzavat 4y ago
  For printing it's not a problem because a string containing unicode will be transparently printed in both Python 2 and 3 (at least on Linux/Mac, not sure how Windows deals with it). It's also not a problem if you only have ASCII strings.
IgorPartola 4y ago
The print function was the simplest part of the transition. For one you could find and replace all instances of it fairly safely across your codebase and you could quickly discover any places where things broke because of a bad replace. That part took like an hour for a large codebase. The Unicode handling on the other hand took ages because string handling is not easily searchable and replacing it requires understanding what the piece of code actually does. So you have it exactly backwards: if the only migration was the print function then it would be a quick and relatively painless process. But fixing the hard thing which was the broken str/byte model was the hard transition. I am curious if you actually went through this transition or if your opinion on this is more based on observation of others’ work.
- zarzavat 4y ago
  Python is a scripting language. Imagine if bash suddenly changed its syntax so that that instead of printing using echo, you now have to write echo(). Sure it’s just a pair of parentheses. But you probably have thousands of shell scripts on your computer. Are you really going to get your hands dirty and risk editing them without knowing what they do? Of course not, you’re just going to revert back to the version of bash that doesn’t require parentheses and sit on it for as long as you possibly can. Code exists in three states: actively maintained, done/mature, and obsolete. Python 3 attacked mature code, forcing developers to either go back into active maintenance or to obsolete it early. I did transition some Python 2 code to 3. But mostly it was uneconomical and risky, so the vast majority of it sat on Python 2.7 until it was no longer needed. I feel that most of the people who had a positive experience with Python 3 were people doing webdev using Django. They were working on monolithic actively maintained projects and so transitioning to v3 was just a normal maintenance activity.
  - IgorPartola 4y ago
    You are correct that my experience is mostly though not exclusively we Django projects. I guess maintaining your code pays off in the long run. Again, you are arguing that running 2to3 and testing your code was hard. I guess that may be true. But having hunted for a ton of subtle Unicode bugs that problem was very worth fixing.
josefx 4y ago
> There is another universe where Python 3 only fixed the unicode strings, and the transition was a huge success and over in a couple of years. Didn't the unicode changes go on until at least Python 3.6? The issue that most C APIs did not care about their byte strings having any encoding at all seemed to cause one headache after another, especially on Posix, where everything touching the operating system could return random bytes. Reducing the scope to unicode wouldn't have sped up the transition one iota.

chaosite 4y ago

Wait, if it didn't use any strings, then it didn't use the print statement either, right?

zarzavat 4y ago
For printing it's not a problem because a string containing unicode will be transparently printed in both Python 2 and 3 (at least on Linux/Mac, not sure how Windows deals with it). It's also not a problem if you only have ASCII strings.

IgorPartola 4y ago

The print function was the simplest part of the transition. For one you could find and replace all instances of it fairly safely across your codebase and you could quickly discover any places where things broke because of a bad replace. That part took like an hour for a large codebase. The Unicode handling on the other hand took ages because string handling is not easily searchable and replacing it requires understanding what the piece of code actually does. So you have it exactly backwards: if the only migration was the print function then it would be a quick and relatively painless process. But fixing the hard thing which was the broken str/byte model was the hard transition. I am curious if you actually went through this transition or if your opinion on this is more based on observation of others’ work.

zarzavat 4y ago
Python is a scripting language. Imagine if bash suddenly changed its syntax so that that instead of printing using echo, you now have to write echo(). Sure it’s just a pair of parentheses. But you probably have thousands of shell scripts on your computer. Are you really going to get your hands dirty and risk editing them without knowing what they do? Of course not, you’re just going to revert back to the version of bash that doesn’t require parentheses and sit on it for as long as you possibly can. Code exists in three states: actively maintained, done/mature, and obsolete. Python 3 attacked mature code, forcing developers to either go back into active maintenance or to obsolete it early. I did transition some Python 2 code to 3. But mostly it was uneconomical and risky, so the vast majority of it sat on Python 2.7 until it was no longer needed. I feel that most of the people who had a positive experience with Python 3 were people doing webdev using Django. They were working on monolithic actively maintained projects and so transitioning to v3 was just a normal maintenance activity.
- IgorPartola 4y ago
  You are correct that my experience is mostly though not exclusively we Django projects. I guess maintaining your code pays off in the long run. Again, you are arguing that running 2to3 and testing your code was hard. I guess that may be true. But having hunted for a ton of subtle Unicode bugs that problem was very worth fixing.

josefx 4y ago

> There is another universe where Python 3 only fixed the unicode strings, and the transition was a huge success and over in a couple of years. Didn't the unicode changes go on until at least Python 3.6? The issue that most C APIs did not care about their byte strings having any encoding at all seemed to cause one headache after another, especially on Posix, where everything touching the operating system could return random bytes. Reducing the scope to unicode wouldn't have sped up the transition one iota.