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Re:No-op statements syntactically valid only since Python X.Y by usr1106 on Monday June 06, 2022 @01:57AM (#31637615)
I learned Python probably over 15 years ago. Haven't used it very much and certainly not followed all the news.

I remember back then it was said the design philosphy was something like there should be one obvious way to code something correctly. In opposite to Perl where the philosohpy was that human thoughts can take weird ways and you should be able to put your thoughts to code directly. (Both characterizations from memory.)

Today I hear little from Perl. And with new syntax added to Python in every version I start to wonder how far away Python is drifting away from that original characterization above.

Re:No-op statements syntactically valid only since Python X.Y by noobermin on Monday June 06, 2022 @02:19AM (#31637699)
One way was never going to work, ever. No real substantive platform of any kind will ever have one way to do something. May be if you're a literalist, there can sometimes be an "obvious way" to do something with emphasis on "obvious," but beyond that, the moment you have more than one library in the ecosystem that does a similar thing, you no longer can do something "one way."

I'm not sure if today that really matters though. I will admit I don't know much about Perl but Perl's death vs Python's life probably might have some influence from design choices but a lot of it just has to do with the libraries you have access to with Python. I know as a scientist, Python is the game in town, that has more to do with why I use it than design.

Re:No-op statements syntactically valid only since Python X.Y by sgk284 on Monday June 06, 2022 @03:29AM (#31638048)
The "one way" philosophy worked really well for Python for 15-20 years.

It was really only during the break-away adoption by the data science community (and other mass audiences) that started adding pressure to bloat the language. The adoption of 3rd party libraries like numpy, which are so critical to modern Python, also destroyed the community's "batteries included" philosophy.

Older Python felt a lot like using FreeBSD, where the whole system is cohesive and designed to work together, whereas modern Python feels a lot more like Linux – a bunch of disparate systems that try to work well together (in the best of times).

Both approaches have their strengths, and the language has certainly improved in some areas, but I prefer the older style.

In any case, it is fascinating to see how mainstream Python is now. Maybe this change in mindset was required for it to take over the world. We've come so far since Paul Graham cited the language as esoteric and its usage a high signal of competence (http://www.paulgraham.com/pypar.html).

Re:No-op statements syntactically valid only since Python X.Y by wheelerof4te on Monday June 06, 2022 @04:02AM (#31638211)
"The adoption of 3rd party libraries like numpy, which are so critical to modern Python, also destroyed the community's "batteries included" philosophy."

You are right and your FreeBSD vs Linux analogy really hits the target.

Thanks to the advancement of hardare and the development of libraries like Numpy, Python has moved from it's scripting niche and became a global, general purpose language.

Was that an error? If we look at the "batteries included" philosophy and the poor state of Python's package management after all these years...I'd say yes.

Re:No-op statements syntactically valid only since Python X.Y by DemocracyFTW2 on Monday June 06, 2022 @06:02AM (#31638693)
When I whined about Python's import system in another comment I completely forgot to add some snark concerning the horrible, horrible state of everything to do with Python package management system. Here again, many failed efforts over the years (setuptools, pip, ...), a terrifyingly convoluted packaging system, and bad, highly complex plans (virtualenv) to heal problems that are self-inflicted
Re:No-op statements syntactically valid only since Python X.Y by jimmaswell on Monday June 06, 2022 @04:33PM (#31645850)
I seldom use Python anymore but the few times I've used pip it's been fine. What went wrong with pip?
Re:No-op statements syntactically valid only since Python X.Y by squar1sm on Monday June 06, 2022 @05:51PM (#31646823)
Asking people to run `pip install` on anything but `poetry` is an anti-pattern to me. Ruby has had bundler for over a decade and this is the pattern that is working for them as well as npm/yarn. Npm comes with node, Cargo comes with Rust so the debate is somewhat reduced.

Since quality of life tools and other soft things are hard to prove, I'll tell my anecdata story point. I sought out any package manager experience in python. I landed on Pipenv which uses pip. It failed to solve the tree. This led me to find poetry and the reason for existing which is exactly my experience. That was 2-3 years ago.

https://github.com/python-poetry/poetry#why

Combine this with asdf and it aligns with most other languages.

  asdf + yarn/npm = javascript
  asdf + poetry = python
  asdf + bundler = ruby
  asdf + cargo = rust
  asdf + mix = elixir
  asdf + shards = crystal
  asdf + go.mod (others) = go
  asdf + composer = php
In legacy (don't break anything) mode, there's still no reason to not switch. I export `requirements.txt` with poetry just for pip legacy reasons and it works great. If I just update some scripts, I could avoid it. It's running all the time in CI, it's exercised quite a bit.

What's wrong with just using pip and requirements.txt? There's no dev section. In addition, bumping deps is not the same. I have a blog post explaining semver updates to a python dev:

https://squarism.com/2021/09/10/sciencing-out-updates/

my strong assertion: Python and Go missed it from the start. That's why it is so confusing. There's no other choice in Rust but Cargo. Rust devs are never confused on how to add a package, semver it. The answer is always Cargo. It's in the tutorial. It's in the book. It's in the culture.

I think I've heard that pip might support the pyproject spec, poetry already does. If you want scripts like npm, you can have that too with "taskipy". You don't have to.

Re:No-op statements syntactically valid only since Python X.Y by mhneu on Monday June 06, 2022 @03:50PM (#31645232)
It's really been a mistake for the Python core team to not figure out a better way of integration with numpy. I'm pretty sure back in the 2000s the numpy team was ready to do work on this.

Syntax integration would be great. It's such a hassle to learn two syntaxes and two data/object models to work with numpy -- as inevitably your code converts from Python objects <-> numpy objects at some point (singletons!), and it makes learners' lives much more difficult than needed.

Re:No-op statements syntactically valid only since Python X.Y by deepsquirrelnet on Tuesday June 07, 2022 @01:00AM (#31650062)
As I recall there were not one, but three libraries providing similar functionality — numpy, numeric and numarray. In the mid-2000s I was using all of them for various reasons. It took quite a while before numpy emerged as the defacto standard.

I wonder if there was no adoption into the language at that time as a result of fractured communities and lack of consensus.

Re:No-op statements syntactically valid only since Python X.Y by xenophonf on Monday June 06, 2022 @10:09AM (#31640705)
Perl's popularity waned because of the whole Perl 6 fiasco, which stole lots of energy from Perl 5, offered no migration path from Perl 5, and eventually evolved into a completely different language. As a result, Perl 5 development stalled, and developers went elsewhere. I personally stopped writing new Perl code around 2005-2006 after learning Python 2 in 2003-2004 (when I was doing a lot of Zope/Plone hacking).

I think Python 3 almost killed Python, too, and for the same reasons. The developers behind 2to3 saved the community, in my opinion, as did the folks who made the painful decision to publish a Python 2 end-of-life date sufficiently far enough into the future that people still using the old runtime had both a sense of urgency and plenty of time to complete their migrations. I finally made the leap to Python 3 around 2016. I'd like to claim that I jumped instead of being pushed, but the reality is that by then, people were developing new stuff I wanted badly on Python 3 exclusively.

Re:No-op statements syntactically valid only since Python X.Y by eesmith on Monday June 06, 2022 @11:40AM (#31641878)
I think "six" proved more useful than 2to3. This made it easier to support both Python 2 and Python 3 in the same code base, which (IMO) resulted in a smoother migration path.
Re:No-op statements syntactically valid only since Python X.Y by xenophonf on Monday June 06, 2022 @11:59AM (#31642150)
You're absolutely right, and again, I think that reinforces how important a good migration path was to Python 3. Without that path, I think there was a real risk of Python dying off same as Perl 5.

It's sad because there was a lot I liked about Perl. I wish that community had better leadership because from my quick glance at the Wikipedia page, it looks like the Perl 7 project is making the same mistakes as Perl 6/Raku did. It's really too bad.

Re:No-op statements syntactically valid only since Python X.Y by at_a_remove on Monday June 06, 2022 @12:57PM (#31642898)
Perl's popularity was already in a nosedive by that point. I was programming in Perl much prior, was on numerous mailing lists, etc. The dropoff was startling.

Frankly, I believe the terrible state of affairs on CPAN was part of the problem, but it was initiated by the "there's more than one way to do it" mentality. If I wanted to do something where it would be a good idea to have a library for that task, I would have to search many candidates, each of which did sixty to eighty percent of whatever, then see which were long-abandoned, did what they actually managed to write match what I needed, etc.

Re:No-op statements syntactically valid only since Python X.Y by marcosdumay on Monday June 06, 2022 @10:53AM (#31641257)
> but a lot of it just has to do with the libraries you have access to with Python

Certainly not. Perl was always the language that had all the libraries. Python only started to get a large ecosystem way after Perl was doomed.

Re:No-op statements syntactically valid only since Python X.Y by eesmith on Monday June 06, 2022 @03:51AM (#31638155)
I view that section as a commentary about the concept of "orthogonally", arising from Algol 68. Quoting van Wijngaarden:

> The number of independent primitive concepts has been minimized in order that the language be easy to describe, to learn, and to implement. On the other hand, these concepts have been applied “orthogonally” in order to maximize the expressive power of the language while trying to avoid deleterious superfluities

Viewing through this lens, the Python Zen's "obvious way" refers to concepts in the language, and not the wider ecosystem which includes libraries.

Re:No-op statements syntactically valid only since Python X.Y by usr1106 on Monday June 06, 2022 @08:47AM (#31639782)
> refers to concepts in the language, and not the wider ecosystem which includes libraries.

Sure, but tests in the submission (not talking about further discussions) are only about the language. And with so much new syntax added over the years I doubt that there can be only one obvious way for many problems.

"I doubt" is just my feeling. I have not make any efforts to demonstrate this by examples. And it wouldn't be easy for me because I am not very fluent with many of the newer features of the language.

Re:No-op statements syntactically valid only since Python X.Y by eesmith on Monday June 06, 2022 @11:36AM (#31641833)
While the tests are about the language, noobermin's comment that I replied to was not.

Here's my summary of the tests:

2.4: generator comprehensions; the obvious way if that's what you need

2.5: if-else expressions; a bit too easily used when if/else statement is more appropriate, but there are times where it's a good fit.

2.7: set notation: {0} is the obvious improvement over set([0])

3.0: ... as a token - I don't really understand why Python changed here. I only use it in indexing. It's not obvious when I would use it at all.

3.1: multiple context managers; the obvious improvement over a multiple indented managers

3.3: yield from list; the obvious improvement over for x in lst: yield lst

3.5: @ operator added for matrix multiplier. Solves a special pain point. Obvious only for that case.

3.6: underscores in numbers. Generally better for larger numbers. Mostly obvious.

3.7: async - I've not done async in Python yet, so can't judge

3.8: x:=expr; the debate that broke van Rossum. Not going there.

3.9: allow more complicated @annotation expressions; more useful than the alternative if that's what you need

3.10: match; no experience with it. I suspect it's more obvious

3.11: more async that I can't judge.

Re:No-op statements syntactically valid only since Python X.Y by anderskaseorg on Monday June 06, 2022 @03:08PM (#31644529)
async/await was actually added in 3.5 (although the @ test in since-3.5.py is shorter). The specific change used by since-3.7.py is that await is now allowed inside an f-string (inside an async function). The specific change used by since-3.11.py is that an async comprehension is now allowed inside a normal comprehension (inside an async function). These changes are, of course, not new primitives—just fixes to allow existing primitives to be combined in ways that should intuitively work.
Re:No-op statements syntactically valid only since Python X.Y by zbentley on Monday June 06, 2022 @11:59AM (#31642139)
For "yield from lst" I think your example should be "for x in lst: yield x".
Re:No-op statements syntactically valid only since Python X.Y by eesmith on Monday June 06, 2022 @02:46PM (#31644148)
Indeed. Thanks!
Re:No-op statements syntactically valid only since Python X.Y by jwilk on Monday June 06, 2022 @01:55PM (#31643555)
You missed 2.6: b-strings
Re:No-op statements syntactically valid only since Python X.Y by eesmith on Monday June 06, 2022 @02:45PM (#31644145)
Yes. Needed for Python 3 compatibility, where it's the "obvious" way to store a binary string.
Re:No-op statements syntactically valid only since Python X.Y by WaxProlix on Monday June 06, 2022 @02:21AM (#31637712)
The mantra was one - and only one - obvious way to do something.

So, there can and should be lots of ways to do things. But always one obvious way, a Happy Path that's not obscured at all or whatever.

Re:No-op statements syntactically valid only since Python X.Y by chrisoverzero on Monday June 06, 2022 @09:20AM (#31640094)
Let’s all stop half-remembering this quote and get it straight from the source:

> There should be one – and preferably only one – obvious way to do it.

> Although that way may not be obvious at first unless you're Dutch.

Re:No-op statements syntactically valid only since Python X.Y by cgriswald on Monday June 06, 2022 @01:47PM (#31643463)
All-in-all I think Python has done a remarkably good job at living up to that quote, with three caveats:

The first is that I think actually achieving a hard-mode form of that quote and maintaining it through the lifetime of the language is impossible in practice and theory. (Even "mostly" living up to the quote is an achievement.)

The second is that I am unsure about the obvious qualifier. Certainly I can recognize pythonic and non-pythonic constructs in python; but whether the difference is actually obvious or just a result of experience combining with community consensus I can't say.

The third is that I don't think the language is Pareto efficient between readability and most other variables. For instance, I've had code criticized as non-pythonic that was just as readable as the offered pythonic version, but had greater run-time efficiency. (To be fair, this is only an issue if you define the 'pythonic' way to be the 'one obvious way'.)

Re:No-op statements syntactically valid only since Python X.Y by PeterisP on Monday June 06, 2022 @02:25AM (#31637737)
Your comment about libraries is quite relevant still - it's about an ideological preference where you preferably would not have many libraries in the ecosystem that do a similar thing without one of them being the default obvious one way to do it. "Batteries included" philosophy is one aspect to ensure that this happens, preferring to have a 'blessed' way to everyone choosing a different library which gets the advantage of each being slightly better tailored for the need at the (significant!) cost of fragmentation and thus readability and maintenance.
Re:No-op statements syntactically valid only since Python X.Y by Scarblac on Monday June 06, 2022 @03:11AM (#31637963)
Numpy is the library that absolutely everything uses for array data. It's not part of the standard library but still.

All the other things built on top that people use Python for are very interoperable because they use the same base data type.

Re:No-op statements syntactically valid only since Python X.Y by js2 on Monday June 06, 2022 @02:26AM (#31637741)

    >>> import this
    The Zen of Python, by Tim Peters

    Beautiful is better than ugly.
    Explicit is better than implicit.
    Simple is better than complex.
    Complex is better than complicated.
    Flat is better than nested.
    Sparse is better than dense.
    Readability counts.
    Special cases aren't special enough to break the rules.
    Although practicality beats purity.
    Errors should never pass silently.
    Unless explicitly silenced.
    In the face of ambiguity, refuse the temptation to guess.
    There should be one-- and preferably only one --obvious way to do it.
    Although that way may not be obvious at first unless you're Dutch.
    Now is better than never.
    Although never is often better than *right* now.
    If the implementation is hard to explain, it's a bad idea.
    If the implementation is easy to explain, it may be a good idea.
    Namespaces are one honking great idea -- let's do more of those!
Re:No-op statements syntactically valid only since Python X.Y by uranusjr on Monday June 06, 2022 @03:45AM (#31638125)
Note that this describes a Zen state (as in the Western colloquial sense) and is supposed to be intentionally self-contradicting to provoke thoughts. It’s sometimes disappointing to see a lot of people follow it as rules or strong suggestions, which completely misses the point.
Re:No-op statements syntactically valid only since Python X.Y by bityard on Monday June 06, 2022 @09:03AM (#31639920)
It seems obvious that they are at least strong suggestions, what makes you think they are not?
Re:No-op statements syntactically valid only since Python X.Y by jofer on Monday June 06, 2022 @10:24AM (#31640902)
It's a matter of how you interpret and use them.

If you think about it as "strong suggestions", then yeah it seems obvious that they're suggestions for how to approach ambiguous situations. However, that's also missing the point a bit.

It's often more useful to think about it as "thought exercises when trying to understand the design philosophy". Note that it deliberately contradicts itself.

Similarly, things like "flat is better than nested" and "sparse is better than dense" are completely false a lot of the time. There are plenty of cases where the opposite is true for practical reasons like memory use or access patterns. The point is not necessarily to make those as statements or suggestions. The point is to give you something to think about. They're more like koans than suggestions.

Think about why and where they're not true as much as why and where they are. And don't take it too seriously, either way! The whole thing of "import this" is tongue in cheek, after all.

Re:No-op statements syntactically valid only since Python X.Y by zlwerq on Monday June 06, 2022 @04:54AM (#31638437)
This hasn't been true for a long time. These days it feels like mentioning the original founding principles of Animal Farm after it went totalitarian.

It is from a different age, when intelligent people like Tim Peters still had influence and there was more of an academic atmosphere. These days it is about warming chairs, getting power, eliminating your enemies and speaking at conferences.

Re:No-op statements syntactically valid only since Python X.Y by isoprophlex on Monday June 06, 2022 @02:51AM (#31637865)
>>> import numpy.polynomial.polynomial.Polynomial as P

NaMeSpAcES ArE ONe HONkInG gReAt IdEa

https://i.redd.it/jsh0ut0mtm391.jpg

Re:No-op statements syntactically valid only since Python X.Y by eloisius on Monday June 06, 2022 @06:07AM (#31638713)
Namespaces are great but Python’s module system being coupled to file system structure kinda sucks. You either have overly-granular modules with manageable files, or you end up with multi-thousand line files that present a reasonable module organization. Or the totally unreasonable granular module structure for reasonable files with a facade set of modules that just reexport things.
Re:No-op statements syntactically valid only since Python X.Y by plq on Monday June 06, 2022 @07:03AM (#31638968)
You can split your big module into modules inside a sub-package and import stuff in the __init__.py file from the submodules to present a nice interface to the library user.

eg instead of:

    namespace.py
        class C1:
        class C2:
do

    namespace/__init__.py
        from .c1 import C1
        from .c2 import C2

    namespace/c1.py
        class C1:

    namespace/c2.py
        class C2:
Re:No-op statements syntactically valid only since Python X.Y by eesmith on Monday June 06, 2022 @03:03PM (#31644438)
What I don't like about this approach is how I'm supposed to refer to something by namespace.C1 but its repr is namespace.c1.C1.

I would prefer if the repr reported its primary public API name, not its internal implementation location.

Re:No-op statements syntactically valid only since Python X.Y by eloisius on Monday June 06, 2022 @07:10AM (#31639013)
That’s what I described as the facade module approach.
Re:No-op statements syntactically valid only since Python X.Y by mikepurvis on Monday June 06, 2022 @08:34AM (#31639660)
What's wrong with facade modules? That seems to be a pretty common pattern, and it allows you to decouple your filesystem structure from module structure while still giving someone reading the source a breadcrumb to follow.

Quite apart from implementation challenges (eg, needing to parse every file in package upfront to know what's in there), how else would you see this working? Are there other interpreted languages that manage this indirection in a more elegant way than having some central file that supplies the mapping information?

Re:No-op statements syntactically valid only since Python X.Y by eloisius on Monday June 06, 2022 @10:27AM (#31640950)
There’s nothing wrong with it, per se, but it is more to maintain, and it’s a confusing indirection to downstream users that need to pry into your code to debug something.

Ruby has its own problems, but I like that the modules are independent from the file that contains them. You can “reopen” a module and declare new classes or constants or whatever. You have freedom (and responsibility) to organize your files in a way that maps to module namespaces. The drawback is the `require “my_file”` doesn’t give you any hint about what you’re importing.

Re:No-op statements syntactically valid only since Python X.Y by throwaway892238 on Monday June 06, 2022 @12:17PM (#31642364)
The module system linked to file structure worked for Perl pretty well. Perl had this crazy idea that different authors should publish packages/modules with the same namespace, e.g.

  IO.pm                      <-- author: Larry Wall
  IO/File.pm                 <-- author: Me
  IO/Socket.pm               <-- author: You
  IO/Socket/INET.pm          <-- author: Larry Wall
  IO/Socket/INET/Daemon.pm   <-- author: Me
Simpler and encourages code reuse. Of course there is duplicate code in CPAN, but you really have to go out of your way to avoid an existing module that can do what you need.
Re:No-op statements syntactically valid only since Python X.Y by emidln on Monday June 06, 2022 @08:54AM (#31639841)
You can organize your packages however you want if you write and register a new module loader.
Re:No-op statements syntactically valid only since Python X.Y by mirekrusin on Monday June 06, 2022 @03:17AM (#31637997)
It violates rule 5 "Flat is better than nested".
Re:No-op statements syntactically valid only since Python X.Y by eesmith on Monday June 06, 2022 @03:40AM (#31638105)
NumPy also imports all of its subpackages, allowing:

  >>> import numpy
  >>> P = numpy.polynomial.polynomial.Polynomial
This results in a high startup cost if you just one one NumPy feature.

I've always thought this ran counter to "Explicit is better than implicit".

The NumPy developers think "practicality beats purity" is more important, and their main use-case is long-running programs where startup costs are slow, which I interpret as meaning their special cases is special enough to break the rules.

Re:No-op statements syntactically valid only since Python X.Y by urthor on Monday June 06, 2022 @07:02AM (#31638966)
Isn't Numpy about making things go fast?

People who expect things to go fast want it all cached up front, for very obvious reasons.

Seems straightforward.

Re:No-op statements syntactically valid only since Python X.Y by eesmith on Monday June 06, 2022 @09:18AM (#31640074)
"Go fast" has multiple dimensions.

For one example, I had a command-line tool which needed to compute something related to hypergeometric distribution. (It's been a few years; I forget the details.)

This available in scipy, which need numpy. Most of my program's run-time was spent importing numpy. (The following timings are best-of-3.)

  % time python -c pass
  0.027u 0.011s 0:00.04 75.0% 0+0k 0+0io 0pf+0w
  % time python -c "import numpy"
  0.212u 0.059s 0:00.17 152.9% 0+0k 0+0io 14pf+0w
  % time python -c "import scipy"
  0.252u 0.077s 0:00.32 100.0% 0+0k 0+0io 14pf+0w
While 0.2 seconds doesn't seem like much to people used to spending hours developing a notebook, or running some large matrix computation, I could make my program 8x faster by writing the dozen or so lines I needed to evaluate that function myself.

Numpy is not about making short-lived programs fast.

In any case, this specific choice of importing all submodules is not to cache things up "for obvious [performance] reasons", because there is no machine performance improvements.

Instead, it's to make the API easier/faster to use. When you're in a notebook and you need numpy.foo.bar() you can just use it, and not have to go up and use an import statement first.

Re:No-op statements syntactically valid only since Python X.Y by urthor on Monday June 06, 2022 @11:28PM (#31649550)
Yeah exactly.

However, what I'd say is that a short launch from rest is an even more obscure use case than the one numpy supports.

numpy has made the correct compromise IMO, optimizing for long lived programs and notebooks.

Re:No-op statements syntactically valid only since Python X.Y by eesmith on Tuesday June 07, 2022 @07:56AM (#31652837)
While my observation is that most other Python packages don't import all subpackages.

"import urllib" does not also import urllib.parse, so you can't do:

  import urllib
  urllib.parse.quote("A&W")
but instead must explicitly import urllib.parse.

scikit-learn supports essentially the same use cases as NumPy and it doesn't import all its subpackages:

  >>> import sklearn
  >>> sklearn.linear_model
  Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
  AttributeError: module 'sklearn' has no attribute 'linear_model'
  >>> import sklearn.linear_model
  >>> sklearn.linear_model
  <module 'sklearn.linear_model' from '[...]sklearn/linear_model/__init__.py'>
Thus leading to my earlier comment:

> The NumPy developers think "practicality beats purity" is more important, and their main use-case is long-running programs where startup costs are slow, which I interpret as meaning their special cases is special enough to break the rules.

Re:No-op statements syntactically valid only since Python X.Y by hoosieree on Monday June 06, 2022 @11:53AM (#31642065)
If you use a single namespace it becomes Monomial.
Re:No-op statements syntactically valid only since Python X.Y by Stormwalker on Monday June 06, 2022 @04:50AM (#31638427)
Not so known fact: Zen of Python refers to internal CPython design, and not to external application of the language itself. So, any new syntax is fine while one can wrap their head around implementation.
Re:No-op statements syntactically valid only since Python X.Y by fulafel on Monday June 06, 2022 @04:54AM (#31638435)
No, it was prompted by a post to comp.lang.python asking for guidance for new Python users. There's a link to that post in the PEP references (https://peps.python.org/pep-0020/)
Re:No-op statements syntactically valid only since Python X.Y by tus666 on Monday June 06, 2022 @03:07AM (#31637939)
Actually Perl's characterization was that the easy things should be easy, and the hard things possible. Sometimes Python could learn from that.

Oh you want to print to stderr hmm?

Re:No-op statements syntactically valid only since Python X.Y by DemocracyFTW2 on Monday June 06, 2022 @05:55AM (#31638659)
Some things that should be easy are ridiculously hard in Python. Regexes for one have a horrible API story. Another one is the import system which I view as a totally broken effort to heal self-inflicted complexity with more complexity. Here is the code I came up when presented with the task to import a module when its name is given:

    def module_from_path( ctx, name, path ):
      ### thx to https://stackoverflow.com/a/50395128/7568091 ###
      ### thx to https://stackoverflow.com/a/67692/7568091 ###
      import importlib
      import importlib.util
      spec                      = importlib.util.spec_from_file_location( name, path )
      module                    = importlib.util.module_from_spec( spec )
      sys.modules[ spec.name ]  = module
      spec.loader.exec_module( module )
      return importlib.import_module( name )
Details may change any time without notice. The complexity here is a consequence of Python's design decision to treat module names as identifiers, not as quoted strings. The import system is full of such poor choices (dot/relative imports, `__init__.py`, `*.pyc` / `*.pyo` files littering one's source directories, and so on)
Re:No-op statements syntactically valid only since Python X.Y by tails4e on Monday June 06, 2022 @07:20AM (#31639076)
Agree on regex. I started in perl many years ago and loved how integrated regexes were. Was appalled that was was a simple one liner in perl turned into multiple lines in python for every regex. Making a powerful tool easy to use means it will be used more.

It would be nice if that flaw could be fixed, as I like coding in python in general

Re:No-op statements syntactically valid only since Python X.Y by eesmith on Monday June 06, 2022 @11:49AM (#31642005)
Here' an ancient hack that showed how that might look like - http://dalkescientific.com/Python/python4ply-tutorial.html#m... .

  count = 0
  t1 = time.time()
  for line in open("nucleosome.pdb"):
    if line =~ m/(ATOM  |HETATM)/:
        count += 1
  print count, "atoms in", time.time()-t1, "seconds"
It used it own PLY-based parser to generate the Python AST.

None of it would work now. :)

Re:No-op statements syntactically valid only since Python X.Y by eesmith on Monday June 06, 2022 @02:54PM (#31644263)
I realize now how much of a hack it is. The portion 'm/(ATOM |HETATM)/' could be part of valid Python expression, as:

  >>> ATOM = HETATM = 1
  >>> m = 2
  >>> m/(ATOM  |HETATM)/1
  2.0
so either m// is enabled only after =~, or there has to be some way to recognize the lexically correct match term -- something more powerful than the "m/[^/]*/[a-z]*" used here.
Re:No-op statements syntactically valid only since Python X.Y by dvdkon on Monday June 06, 2022 @09:33AM (#31640220)
I have to say I really like Python's module system. Modules as objects, scoped import by default and filesystem-backed module resolution (+sys.path) are all good choices in my opinion. Cosmetic warts like __pycache__ are unfortunate, but not deal-breakers.
Re:No-op statements syntactically valid only since Python X.Y by dspillett on Monday June 06, 2022 @03:34AM (#31638070)
My main memory of perl (I used it for CGI and local CLI tooling back in the day) was that it was usually very terse, to the point of being a write-only language. I learned an important lesson with it: the more clever you feel writing code, the more you are likely to hate maintaining it after a few months away!
Re:No-op statements syntactically valid only since Python X.Y by xyzzy123 on Monday June 06, 2022 @05:36AM (#31638597)
There was a long time period (IMHO good few years in early 2000s) where Python looked better on paper but Perl was still better for production.

All the Perl libraries for doing certain things (db access, web stuff, process management) were "actually battle tested" and worked well even if they were utterly unreadable. Python looked a lot nicer but when you tried to do any real work with it everything seemed to leak memory or give you continuous paper cuts - and it was a lot slower.

I made the switch to Python eventually but it took a while.

Re:No-op statements syntactically valid only since Python X.Y by dspillett on Monday June 06, 2022 @12:32PM (#31642587)
> (IMHO good few years in early 2000s)

That tallies with when I was using Perl (late 90s / early 00s). Python was very much on the up in that time but I didn't feel compelled to switch, then DayJob and personal projects took me away from such thing completely (DayJob was Windows/VB6/IIS/ASP based, home web stuff went PHP for a while and admin stuff to Bash).

Re:No-op statements syntactically valid only since Python X.Y by adrianmonk on Monday June 06, 2022 @03:24AM (#31638018)
Perl also has the motto "there's more than one way to do it".

https://en.wikipedia.org/wiki/There%27s_more_than_one_way_to...

Re:No-op statements syntactically valid only since Python X.Y by omoikane on Monday June 06, 2022 @11:59AM (#31642145)
This is also the motto I learned. This would explain Python's motto of "There Is Only One Way to Do It".

(It's a joke due from this page: http://james-iry.blogspot.com/2009/05/brief-incomplete-and-m..., actual motto is "there should be one -- and preferably only one -- obvious way to do it")

Re:No-op statements syntactically valid only since Python X.Y by bvrmn on Monday June 06, 2022 @03:22AM (#31638012)
What's wrong with printing to stderr in python?
Re:No-op statements syntactically valid only since Python X.Y by eesmith on Monday June 06, 2022 @03:44AM (#31638121)
Agreed!

In fact, I think this makes it so all print() calls by default write to stderr:

  >>> import sys, functools, builtins
  >>> real_print = print
  >>> builtins.print = functools.partial(real_print, file=sys.stderr)
  >>> print("Hello")
  Hello
Re:No-op statements syntactically valid only since Python X.Y by abdusco on Monday June 06, 2022 @06:05AM (#31638703)
Or use logging module as you should, which prints to stderr by default.

    import logging
    logging.basicConfig()

    logging.info('something happened')
Re:No-op statements syntactically valid only since Python X.Y by prirun on Monday June 06, 2022 @10:01AM (#31640596)
The problem for me with logging is that it's slow for production code:

Python 2.7.15 Linux (logging is 60x slower):

  [root@hbtest ~]# py -m timeit -s 'import logging' "logging.info('something happened')"
  1000000 loops, best of 3: 1.31 usec per loop

  [root@hbtest ~]# py -m timeit -s 'import sys; debug = False' "if debug: print >>sys.stderr, 'something happened'"
  10000000 loops, best of 3: 0.0216 usec per loop
Python 2.7.15 OSX (logging is 71x slower):

  $ py -m timeit -s 'import logging' "logging.info('something happened')"
  1000000 loops, best of 3: 0.925 usec per loop

  [jim@mbp hbrel]$ py -m timeit -s 'import sys; debug = False' "if debug: print >>sys.stderr, 'something happened'"
  100000000 loops, best of 3: 0.013 usec per loop
Python 3.6.8 Linux (logging is 99x slower):

  [root@hbtest ~]# python3 -m timeit -s 'import logging' "logging.info('something happened')"
  1000000 loops, best of 3: 1.62 usec per loop

  [root@hbtest ~]# python3 -m timeit -s 'import sys; debug = False' "if debug: print >>sys.stderr, 'something happened'"
  100000000 loops, best of 3: 0.0163 usec per loop
And, as usual, Python 3 is 25% slower than Python 2 for the logging case (but 2x faster for the noop if debug case). I hope the recent efforts to increase Python 3 performance are successful.
Re:No-op statements syntactically valid only since Python X.Y by mixmastamyk on Monday June 06, 2022 @10:45AM (#31641148)
Microseconds are not important unless in a very tight loop. Avoid there and/or make a shortcut beforehand.
Re:No-op statements syntactically valid only since Python X.Y by eesmith on Monday June 06, 2022 @11:43AM (#31641926)
And we don't know why tus666 wants to print to stderr, nor what the issue was with Python, so this digression seems built on sand.
Re:No-op statements syntactically valid only since Python X.Y by 8organicbits on Monday June 06, 2022 @09:40AM (#31640296)
I don't think I follow the stderr comment. Isn't it just:

Perl

    print STDERR "foo"
Python

    print(file=sys.stderr, "foo")
Those look fairly similar. I prefer that print() is obviously a function call and file is a named parameter so the purpose is clear.
Re:No-op statements syntactically valid only since Python X.Y by tus666 on Monday June 06, 2022 @03:38PM (#31645039)
Well in Perl there is...

warn("foo")

In Python you have to at least:

- remember not to forget to import sys - remember the file= syntax for the print statement - type about 10 extra characters

Bunch of annoying stuff when you are hurriedly debugging something...

Re:No-op statements syntactically valid only since Python X.Y by tyingq on Monday June 06, 2022 @09:44AM (#31640341)
The file=sys.stderr came with Python 3. Because of that, I tend to see sys.stderr.write("foo\n") more often.
Re:No-op statements syntactically valid only since Python X.Y by jerdfelt on Monday June 06, 2022 @11:45AM (#31641964)
Python 2 was even more terse with it's print statement

    print >>sys.stderr, "foo"
Re:No-op statements syntactically valid only since Python X.Y by marcosdumay on Monday June 06, 2022 @10:57AM (#31641305)
Or, on the first Python3 releases, do you want to output binary data at all?
Re:No-op statements syntactically valid only since Python X.Y by Aloha on Monday June 06, 2022 @02:11AM (#31637656)
At some point those two philosophies cross over, that's where you end up with bash or even php, there are several right ways, and several wrong ways, and all of them work.
Re:No-op statements syntactically valid only since Python X.Y by planckscnst on Monday June 06, 2022 @08:59PM (#31648563)
I don't ever think Python has lived up to that tenet. If they did, then there wouldn't be a million pull requests with comments saying something to the effect of "the pythonic way to do this is..." or "pipXYZ says you should/shouldn't..."
Re:No-op statements syntactically valid only since Python X.Y by tqlz on Monday June 06, 2022 @04:04AM (#31638220)
Development is no longer about the language or elegance. It is about the old boys and their subordinates getting and maintaining positions at large corporations.

Which requires politics, churn, adding non-essential features and covering up mistakes by the old boys.