Really, changing a Python project is not pretty, because speed and memory usage guarantees vary wildly between releases. One factor is that CPython is constantly being rewritten.
And that does not even cover projects that depend on 20 PyPI packages, which introduces practically guaranteed breakage.
> One factor is that CPython is constantly being rewritten.
Exactly. I have an impression that the programmers as the whole already spent significant time only to develop and maintain different solutions only to manage different Python versions and dependencies in production environments, which were maybe much less needed exactly with some better "discipline" in the Python development itself.
On another side, Python won many hearts over Perl 5 which is much more stable, but "appears to be" harder. Interestingly, Perl actually forces a programmer to "care more" (i.e. be more precise): the reference to something requires different notation than the direct use of something, the use of the array requires different notation than the use of the scalar etc... it actually has "some kind" of typing enforced by the language and explicit in every line. In my personal experience, I have much more "trust" in a 'biggish' Perl program than in a that big Python program to behave "exactly how I'd expect it" (e.g. in the sense that Perl doesn't produce as easy "exceptions" and whoever wrote it had to think more about the correctness than for Python, especially if "use strict" was used, which has stronger guarantees about the typos in variable names than Python). Going further, however, C-like (actually Algol-like) compiled languages simply allow much more than the scripting languages, regarding the smallness of what is eventually produced. E.g. Busybox ( https://busybox.net/ ) has to be written in C or something very close to C. Free Pascal http://wiki.freepascal.org/Platform_list is actually also very practical language for many use-cases.
Really, changing a Python project is not pretty, because speed and memory usage guarantees vary wildly between releases. One factor is that CPython is constantly being rewritten.
And that does not even cover projects that depend on 20 PyPI packages, which introduces practically guaranteed breakage.