6 ms·

The Python Standard Library - Where Modules Go To Die

122 points by b14ck 14y ago

zeeg 14y ago
This happens in every language. I dont think it's that big of a deal. In all honesty, you could continue to maintain a package outside of stdlib, and just require a newer version (which gets installed via the standard packaging tools). This type of behavior isn't well defined in Python, but it's not unrealistic to think it could happen.
- true_religion 14y ago
  How is it not well defined in Python?
  - zeeg 14y ago
    Well it would work just fine, but you'd always end up requiring the external dependency even if you didn't need to. For example, let's say there was a new urllib released (its still called urllib). It's now version 2.0, but the stdlib version is 1.0. If your package said "I need urllib==1.0", it would have know way of understanding that the version was already included within the standard library. That said, it would download the correct package (assuming it existed) and work just fine.
    - anthonyb 14y ago
      > it would have know way of understanding that the version was already included within the standard library Other than by introspecting which packages are installed, that is. Most of them will have a VERSION, __version__ or _version attribute which tells you.
      - jmoiron 14y ago
        This is available via the pkg-info in all installed packages; iirc version is required for distutils, and there is pep386 for version number format, so it should be possible to determine version number as well as compare them for all well-behaved packages. There is even a package which will find and parse pkg-info for an installed package called pkginfo: http://pypi.python.org/pypi/pkginfo http://pypi.python.org/pypi/pkginfo
        anthonyb 14y ago
        GP was talking about built in modules in the standard library. I don't think they use distutils, but many of them still have some sort of version number.
    - slurgfest 14y ago
      Since it would work just fine, what is the problem you are trying to solve? Having to download too much stuff?
100k 14y ago
This has kind of happened in Ruby, too. Fortunately, Ruby gems are super easy to install and the standard library got some much-needed spring cleaning in 1.9. Python could use the same. There have been many times where I've wanted to do some simple task that would be made easier with an external library (like Requests) but I'm not going to bother dealing with the Python module install pain for a one-off task.
- lars512 14y ago
  I find the opposite. Installing a useful module for a once-off task is a no brainer, since I won't have to worry about whether I'm introducing some long-term dependency I'll have to maintain. The real issue is in discovering that a better option exists in the first place.
  - 100k 14y ago
    And then you have to deploy it to the server or someone else's computer and it sucks.
    - lloeki 14y ago
      pip freeze works even without virtualenv. Expunge things you know don't matter, and send to third party/deploy, which then just has to run pip install -r requirements.txt.
- atdt 14y ago
  > the Python module install pain for a one-off task. "pip install requests" ?
  - RegEx 14y ago
    Unfortunately, it seems the official documentation on installing Python modules[0] makes absolutely no mention of pip or even easy_install. Seems like something that should be there, right? [0]: http://docs.python.org/install/ http://docs.python.org/install/
chimeracoder 14y ago
> An overstatement, certainly, but with more than a germ a truth. Once a library is enshrined in the standard set, it can’t change radically because too many programs rely on it—and its bugs, idiosyncrasies, and complications—remaining stable. That's a problem inherent in the standardization process, though - it's all but contradictory to have something be both 'standard' and 'continuously improving'. Once something enters the standard, does anyone propose a better way of removing cruft without constantly deprecating everything, rendering the concept of a 'standard' somewhat meaningless?
- lloeki 14y ago
  Things come and go, and we have seen a number of deprecations in python already. urllib predates urllib2, while subprocess deprecates a number of things itself that really came from C. getopt was a port of the eponymous C library, which optparse meant to replace, which was itself deprecated on favor of argparse. I would really not be surprised to see envoy, requests and so on come up in the standard lib at some point.
bunnyhero 14y ago
The permalink for the article is http://www.leancrew.com/all-this/2012/04/where-modules-go-to-die/ http://www.leancrew.com/all-this/2012/04/where-modules-go-to... (the posted link is actually the home page of the blog).
atdt 14y ago
The fact that the standard library is well-maintained, carefully debugged, and backward-compatible is a far stronger indicator of Python's awesomeness than the existence of shiny, new libraries. Hackers naturally gravitate toward high-visibility projects with brave horizons and bold scopes. By contrast, it is incredibly hard to find the motivation to update, for the umpteenth time, a warty API -- and that's precisely the reason why contributions of the latter sort are the truer test of the vitality of a language's ecosystem.
- JoachimSchipper 14y ago
  It is stable, but there are some really nasty warts. To pick just one that bites Python programmers all the time: by default, the ssl library does not validate the server certificate at all. Not validating the certificate makes SSL/TLS almost useless. But this is still the default (see http://docs.python.org/dev/library/ssl.html#socket-creation http://docs.python.org/dev/library/ssl.html#socket-creation, "CERT_NONE"), because the standard library is "stable".
  - jordanb 14y ago
    On the contrary, the vast majority of the time, when one is using SSL, they're using it because they want encryption, rather than identification. The certificate system surrounding SSL is a complete mess. It does virtually nothing other than trigger false positives for people who who haven't paid the appropriate "security partner." The very rare person who is actually using SSL for identification rather than just to establish an encrypted TCP connection, and therefore cares about certificates, can change the default. PS: I know the standard response to this, that encryption without identification is useless, because without identification your counter-party might be Eve. In reality, in the real world, that doesn't happen. MITM attacks are extremely rare. And the real Eves on the net (phishers) can easily obtain signed certificates that will fool pretty much any end user.
    - jvdongen 14y ago
      Not to pick on you per se, but this reasoning is often seen in relation to SSL (or encryption in general) and is dangerously wrong. Encryption without identification and authentication of your communication partners is useless. You may very well end up with a very secure link with the wrong communication partner (google 'man-in-the-middle-attack'). I agree that the (public) CA system is a mess, however especially with machine-to-machine communication it is very easy to generate, sign and use your own certificates. And contrary to popular belief, self-signed certificates are not any less secure than public CA signed ones. Both have their own use-case though. If someone cares I'll be happy to explain the above points in more detail.
norswap 14y ago
The thing with python standard library is that it is crapily documented imho. I often can't make heads or tails of it, while I have a much simpler time with any other language (you name it: Java, Ruby, PHP, C, Scala, Lisp, ...).
- aslewofmice 14y ago
  I felt that way about some of the standard documentation but was relieved to find: http://www.doughellmann.com/PyMOTW/ http://www.doughellmann.com/PyMOTW/ I also highly recommend checking out Doug Hellman's book 'The Python Standard Library by Example'. He presents every (or almost every) standard library module with simple explanations and plenty of examples.
  - zeeg 14y ago
    I've never seen this before, but that is an AMAZING improvement on the standard docs
  - deleted 14y ago
    [deleted]
  - chaostheory 14y ago
    Nice post. This is way better than the standard docs. Having lots of examples really helps.
- TazeTSchnitzel 14y ago
  The Python standard library has great documentation. Except for some of the "batteries included" stuff. urllib2? Ouch.
  - norswap 14y ago
    That was indeed the kind of stuff I had in mind.
nkoren 14y ago
I'm not really a Python programmer, but a hacker who occasionally has cause to pick up Python scripts and do stuff with them. Perhaps I've been unlucky, but every time I've done this, it's turned into a profoundly frustrating exercise. There have always been dependencies outside the standard library, and those have had dependencies -- which more often than not, are incompatible with whatever version of Python my environment is set up for. I've frequently run across scripts with dependencies that somehow only execute in mutually incompatible versions of Python, which always makes for an exceedingly aggravating day of programming. As much as people love to bash PHP -- and I agree that it's pretty awful as a language -- its standard library is so comprehensive, backwards-compatible, and superbly-documented that I have never had a comparably aggravating experience with it. The same is true of Javascript: a language with warts, but whenever I try something, it Just Works. Like I say, perhaps I've just been unlucky, but my distinct impression of Python has been that it's a beautiful language surrounded by a particularly problematic ecosystem of incompatible libraries and sparse documentation. I suspect that the Python community would benefit from paying less attention to the purity of the language, and a lot more attention to the quality of everything surrounding it.
- heretohelp 14y ago
  I think you've really just been unlucky. I've had the same experience before, but chiefly with Ruby. Interestingly, my problems with this in both Python and Ruby have evaporated once I got in the habit of using virtualenv/rb-env/rvm for my development environment. Python is about the cleanest/nicest experience I have in any language, for the record. Only language that comes close is Clojure. Leiningen is...legendary.
  - darklajid 14y ago
    What is Leinigen offering over Maven? Isn't it based on the same stuff? That said: Leiningen & npm _are_ really nice solutions for me.
  - xaa 14y ago
    I would argue that Python's approach is FAR better than Clojure/Leiningen's "no batteries included" approach. Suppose you want to do a very common task like parse some XML. In Clojure, the workflow is: 1. Go to Github or Clojars, find the latest version number of clojure.data.xml 2. Add this version number to your project.clj 3. Lein deps and restart the repl 4. Re-acquire whatever REPL data you had In Python, it's: 1. import xml.{sax,dom,etree} And, paradoxically, the availability of all these different versions of libraries in Clojure leads to MORE conflicts between libraries than would otherwise be the case, not less. In Python, you may not agree that, say, the "os" or "subprocess" modules are optimal -- but by golly, they're consistent.
IgorPartola 14y ago
Agreed with the OP. The following is a shameless plug: Python's ConfigParser module is a pain to use. It provides no validation, only supports a limited number of types of data you can retrieve, etc. Similarly, getopt vs optparse vs argparse is a mess. getopt is universal: not only is it going to be in all versions of Python, but it is also the same library available in virtually every other language. The problem with it is that it is not declarative, so you will typically see a giant if/elif statement that goes with it. argparse/optparse are better, but aren't universal even between versions of Python, though argparse has been backported and is available via pypi. To unify all this into one convenient module, I ended up writing http://ipartola.github.com/groper/ http://ipartola.github.com/groper/. groper lets you specify your parameters declaratively, and if you specify defaults, use them right away without having to create/modify a config file. It automatically figures out the priority of arguments: cmd > config > defaults. It also has some niceties such as the ability to automatically generate usage strings, give the user intelligent error messages, generate sample config files, etc.
- slurgfest 14y ago
  I don't understand why I shouldn't be using argparse. Just using argparse means no mess of 'getopt vs optparse vs argparse' because I am not using all those other libraries. I don't see anything seriously wrong for argparse. How does it help me to use a third party module rather than argparse?
  - IgorPartola 14y ago
    Using argparse is probably the safest approach. However, argparse does not work with config files; groper does. So if you have more than a half-dozen options, you should use groper (or something similar).
eliben 14y ago
Yes, for a language as widely deployed and used as Python, retaining backwards compatibility and stability is more important than adding new and shiny tools to the stdlib at a faster pace. Users rely on the fact that a module in stdlib will remain there and will remain stable for a long time. More modules means more maintainers, and Python is an open-source project developed by volunteers. It's that simple. I'm not sure what the solution this article proposes is. The tradeoff between "coolness" and "stability" is inherently difficult, and I'm sure Python is not the only language "suffering" from it. After all, it's quite easy to install a new Python module, and not much harder to distribute it with your application (for web apps it's even easier), so what is the problem?
agentultra 14y ago
I've heard core Python developers tell people not to worry about getting a module into the stdlib. The problem being that once the module is there it won't be able to change much. APIs have the exact same problem. If you change it, you're changing other peoples' software. Tight coupling. Is it a terrible way to write software? Maybe... but perhaps that's a different discussion. I think the requests library is amazing. It has a much more simple API than urllib/urllib2. Does it need to replace those modules in the stdlib? I hope not! There are only three reasons I would write a module/package that depended solely on stdlib: 1. The module/package would be distributed primarily through package management systems. 2. The installation of my module needs to avoid depending on anything else outside of a base python installation. 3. The module or package will need to be supported for a long time and will likely not be updated frequently. The first case is because you can't control what versions of third-party libraries the package manager will make available. Some might run your setuptools script while others may not. It's just easier to live with the cruft/warts of the stdlib and be sure that they'll always be there. The second case covers a very unique situation. Modules and libraries written with this constraint are typically targeting one of two different kinds of developers. The first are the beginners who may not know about development environments and versioning. The other are experienced developers who want a minimalist script for their little one-off utility. Both should require zero dependency installation if possible. The final case is harder to define up front. If you're writing something that you expect to run for a long time and receive little maintenance (ie: cron scripts, tools, etc) then you don't want to deal with API updates breaking your code. Fire and forget is what a long-term stable API gets you.
EvilTerran 14y ago
It's funny, I've had the opposite problem. I was trying to write an IRC bot in Python, noted there didn't seem to be a standard library module for the IRC protocol, and so found myself looking at this: http://pypi.python.org/pypi?%3Aaction=search&term=IRC http://pypi.python.org/pypi?%3Aaction=search&term=IRC That's 400+ results - at least 20 of which are actually IRC protocol modules. There's no way of telling how mature each one actually is 'til you download it. It turned out the first three I tried were undocumented, buggy, incomplete, or otherwise no good. So I gave up on PyPi and hacked it as an xchat plugin instead. ---------------- Perhaps the way forward would be styling your package repo after, say, addons.mozilla.org -- add just enough community functionality (as in ratings/reviews/"times downloaded" counters/etc) to allow the occasional gems to rise to the top of the muck. Once one solution for a given problem has been established as the best (well, most popular), that'll get more eyeballs on its internals as well, and it'll only increase its lead until it's de facto standard -- but the possibility is still there for a newcomer to dethrone it if it's genuinely better. And meanwhile, both can exist side-by-side without causing ugly compatibility issues.
- slurgfest 14y ago
  I believe that PyPI used to have some kind of popularity contest functionality that got killed. I have to say I'm not sure that selecting the package you want to use is really the problem which PyPI needs to solve. It isn't the app store. That said, PyPI does provide a 'weight' in searches, which seems to track with popularity and freshness somehow.
  - EvilTerran 14y ago
    The title text on "weight" says "Occurrence of search term weighted by field (name, summary, keywords, description, author, maintainer)". So, not popularity/freshness, just a rough metric for how well it matches your search. Indeed, PyPI might not be the right place for a community rating system -- perhaps a site could be built on top of it to provide that sort of functionality.
daxelrod 14y ago
Permalink to this post: http://www.leancrew.com/all-this/2012/04/where-modules-go-to-die/ http://www.leancrew.com/all-this/2012/04/where-modules-go-to... (The current article link goes to the front page of the author's blog.)
makecheck 14y ago
Every language's standard library needs a "current best practices" concept, even if it's just a well-maintained document and not something structural like a special namespace. I think the Python "decorator" concept goes a long way toward cleaning up code. Basically you can add a decorator to a routine that you've deprecated so that it will complain if it's actually used (you can even include advice on what would be a good replacement call). As far as cleaning up what's installed as standard, it's not really practical to remove anything (the fact that it stays is one of the attractive things about Python in old code bases). What you can do though is define a preferred namespace, e.g. "preferred"; this would physically contain only those libraries that are recommended, and perhaps even forked copies of modules that only contain the functions that should be used. This gives programs the option to explicitly import from "preferred" and request purity over long-term stability.

122 points by b14ck 14y ago

zeeg 14y ago

This happens in every language. I dont think it's that big of a deal. In all honesty, you could continue to maintain a package outside of stdlib, and just require a newer version (which gets installed via the standard packaging tools). This type of behavior isn't well defined in Python, but it's not unrealistic to think it could happen.

true_religion 14y ago
How is it not well defined in Python?
- zeeg 14y ago
  Well it would work just fine, but you'd always end up requiring the external dependency even if you didn't need to. For example, let's say there was a new urllib released (its still called urllib). It's now version 2.0, but the stdlib version is 1.0. If your package said "I need urllib==1.0", it would have know way of understanding that the version was already included within the standard library. That said, it would download the correct package (assuming it existed) and work just fine.
  - anthonyb 14y ago
    > it would have know way of understanding that the version was already included within the standard library Other than by introspecting which packages are installed, that is. Most of them will have a VERSION, __version__ or _version attribute which tells you.
    - jmoiron 14y ago
      This is available via the pkg-info in all installed packages; iirc version is required for distutils, and there is pep386 for version number format, so it should be possible to determine version number as well as compare them for all well-behaved packages. There is even a package which will find and parse pkg-info for an installed package called pkginfo: http://pypi.python.org/pypi/pkginfo http://pypi.python.org/pypi/pkginfo
      - anthonyb 14y ago
        GP was talking about built in modules in the standard library. I don't think they use distutils, but many of them still have some sort of version number.
  - slurgfest 14y ago
    Since it would work just fine, what is the problem you are trying to solve? Having to download too much stuff?

100k 14y ago

This has kind of happened in Ruby, too. Fortunately, Ruby gems are super easy to install and the standard library got some much-needed spring cleaning in 1.9. Python could use the same. There have been many times where I've wanted to do some simple task that would be made easier with an external library (like Requests) but I'm not going to bother dealing with the Python module install pain for a one-off task.

lars512 14y ago
I find the opposite. Installing a useful module for a once-off task is a no brainer, since I won't have to worry about whether I'm introducing some long-term dependency I'll have to maintain. The real issue is in discovering that a better option exists in the first place.
- 100k 14y ago
  And then you have to deploy it to the server or someone else's computer and it sucks.
  - lloeki 14y ago
    pip freeze works even without virtualenv. Expunge things you know don't matter, and send to third party/deploy, which then just has to run pip install -r requirements.txt.
atdt 14y ago
> the Python module install pain for a one-off task. "pip install requests" ?
- RegEx 14y ago
  Unfortunately, it seems the official documentation on installing Python modules[0] makes absolutely no mention of pip or even easy_install. Seems like something that should be there, right? [0]: http://docs.python.org/install/ http://docs.python.org/install/

chimeracoder 14y ago

> An overstatement, certainly, but with more than a germ a truth. Once a library is enshrined in the standard set, it can’t change radically because too many programs rely on it—and its bugs, idiosyncrasies, and complications—remaining stable. That's a problem inherent in the standardization process, though - it's all but contradictory to have something be both 'standard' and 'continuously improving'. Once something enters the standard, does anyone propose a better way of removing cruft without constantly deprecating everything, rendering the concept of a 'standard' somewhat meaningless?

lloeki 14y ago
Things come and go, and we have seen a number of deprecations in python already. urllib predates urllib2, while subprocess deprecates a number of things itself that really came from C. getopt was a port of the eponymous C library, which optparse meant to replace, which was itself deprecated on favor of argparse. I would really not be surprised to see envoy, requests and so on come up in the standard lib at some point.

bunnyhero 14y ago

The permalink for the article is http://www.leancrew.com/all-this/2012/04/where-modules-go-to-die/ http://www.leancrew.com/all-this/2012/04/where-modules-go-to... (the posted link is actually the home page of the blog).

atdt 14y ago

The fact that the standard library is well-maintained, carefully debugged, and backward-compatible is a far stronger indicator of Python's awesomeness than the existence of shiny, new libraries. Hackers naturally gravitate toward high-visibility projects with brave horizons and bold scopes. By contrast, it is incredibly hard to find the motivation to update, for the umpteenth time, a warty API -- and that's precisely the reason why contributions of the latter sort are the truer test of the vitality of a language's ecosystem.

JoachimSchipper 14y ago
It is stable, but there are some really nasty warts. To pick just one that bites Python programmers all the time: by default, the ssl library does not validate the server certificate at all. Not validating the certificate makes SSL/TLS almost useless. But this is still the default (see http://docs.python.org/dev/library/ssl.html#socket-creation http://docs.python.org/dev/library/ssl.html#socket-creation, "CERT_NONE"), because the standard library is "stable".
- jordanb 14y ago
  On the contrary, the vast majority of the time, when one is using SSL, they're using it because they want encryption, rather than identification. The certificate system surrounding SSL is a complete mess. It does virtually nothing other than trigger false positives for people who who haven't paid the appropriate "security partner." The very rare person who is actually using SSL for identification rather than just to establish an encrypted TCP connection, and therefore cares about certificates, can change the default. PS: I know the standard response to this, that encryption without identification is useless, because without identification your counter-party might be Eve. In reality, in the real world, that doesn't happen. MITM attacks are extremely rare. And the real Eves on the net (phishers) can easily obtain signed certificates that will fool pretty much any end user.
  - jvdongen 14y ago
    Not to pick on you per se, but this reasoning is often seen in relation to SSL (or encryption in general) and is dangerously wrong. Encryption without identification and authentication of your communication partners is useless. You may very well end up with a very secure link with the wrong communication partner (google 'man-in-the-middle-attack'). I agree that the (public) CA system is a mess, however especially with machine-to-machine communication it is very easy to generate, sign and use your own certificates. And contrary to popular belief, self-signed certificates are not any less secure than public CA signed ones. Both have their own use-case though. If someone cares I'll be happy to explain the above points in more detail.

norswap 14y ago

The thing with python standard library is that it is crapily documented imho. I often can't make heads or tails of it, while I have a much simpler time with any other language (you name it: Java, Ruby, PHP, C, Scala, Lisp, ...).

aslewofmice 14y ago
I felt that way about some of the standard documentation but was relieved to find: http://www.doughellmann.com/PyMOTW/ http://www.doughellmann.com/PyMOTW/ I also highly recommend checking out Doug Hellman's book 'The Python Standard Library by Example'. He presents every (or almost every) standard library module with simple explanations and plenty of examples.
- zeeg 14y ago
  I've never seen this before, but that is an AMAZING improvement on the standard docs
- deleted 14y ago
  [deleted]
- chaostheory 14y ago
  Nice post. This is way better than the standard docs. Having lots of examples really helps.
TazeTSchnitzel 14y ago
The Python standard library has great documentation. Except for some of the "batteries included" stuff. urllib2? Ouch.
- norswap 14y ago
  That was indeed the kind of stuff I had in mind.

nkoren 14y ago

I'm not really a Python programmer, but a hacker who occasionally has cause to pick up Python scripts and do stuff with them. Perhaps I've been unlucky, but every time I've done this, it's turned into a profoundly frustrating exercise. There have always been dependencies outside the standard library, and those have had dependencies -- which more often than not, are incompatible with whatever version of Python my environment is set up for. I've frequently run across scripts with dependencies that somehow only execute in mutually incompatible versions of Python, which always makes for an exceedingly aggravating day of programming. As much as people love to bash PHP -- and I agree that it's pretty awful as a language -- its standard library is so comprehensive, backwards-compatible, and superbly-documented that I have never had a comparably aggravating experience with it. The same is true of Javascript: a language with warts, but whenever I try something, it Just Works. Like I say, perhaps I've just been unlucky, but my distinct impression of Python has been that it's a beautiful language surrounded by a particularly problematic ecosystem of incompatible libraries and sparse documentation. I suspect that the Python community would benefit from paying less attention to the purity of the language, and a lot more attention to the quality of everything surrounding it.

heretohelp 14y ago
I think you've really just been unlucky. I've had the same experience before, but chiefly with Ruby. Interestingly, my problems with this in both Python and Ruby have evaporated once I got in the habit of using virtualenv/rb-env/rvm for my development environment. Python is about the cleanest/nicest experience I have in any language, for the record. Only language that comes close is Clojure. Leiningen is...legendary.
- darklajid 14y ago
  What is Leinigen offering over Maven? Isn't it based on the same stuff? That said: Leiningen & npm _are_ really nice solutions for me.
- xaa 14y ago
  I would argue that Python's approach is FAR better than Clojure/Leiningen's "no batteries included" approach. Suppose you want to do a very common task like parse some XML. In Clojure, the workflow is: 1. Go to Github or Clojars, find the latest version number of clojure.data.xml 2. Add this version number to your project.clj 3. Lein deps and restart the repl 4. Re-acquire whatever REPL data you had In Python, it's: 1. import xml.{sax,dom,etree} And, paradoxically, the availability of all these different versions of libraries in Clojure leads to MORE conflicts between libraries than would otherwise be the case, not less. In Python, you may not agree that, say, the "os" or "subprocess" modules are optimal -- but by golly, they're consistent.

IgorPartola 14y ago

Agreed with the OP. The following is a shameless plug: Python's ConfigParser module is a pain to use. It provides no validation, only supports a limited number of types of data you can retrieve, etc. Similarly, getopt vs optparse vs argparse is a mess. getopt is universal: not only is it going to be in all versions of Python, but it is also the same library available in virtually every other language. The problem with it is that it is not declarative, so you will typically see a giant if/elif statement that goes with it. argparse/optparse are better, but aren't universal even between versions of Python, though argparse has been backported and is available via pypi. To unify all this into one convenient module, I ended up writing http://ipartola.github.com/groper/ http://ipartola.github.com/groper/. groper lets you specify your parameters declaratively, and if you specify defaults, use them right away without having to create/modify a config file. It automatically figures out the priority of arguments: cmd > config > defaults. It also has some niceties such as the ability to automatically generate usage strings, give the user intelligent error messages, generate sample config files, etc.

slurgfest 14y ago
I don't understand why I shouldn't be using argparse. Just using argparse means no mess of 'getopt vs optparse vs argparse' because I am not using all those other libraries. I don't see anything seriously wrong for argparse. How does it help me to use a third party module rather than argparse?
- IgorPartola 14y ago
  Using argparse is probably the safest approach. However, argparse does not work with config files; groper does. So if you have more than a half-dozen options, you should use groper (or something similar).

eliben 14y ago

Yes, for a language as widely deployed and used as Python, retaining backwards compatibility and stability is more important than adding new and shiny tools to the stdlib at a faster pace. Users rely on the fact that a module in stdlib will remain there and will remain stable for a long time. More modules means more maintainers, and Python is an open-source project developed by volunteers. It's that simple. I'm not sure what the solution this article proposes is. The tradeoff between "coolness" and "stability" is inherently difficult, and I'm sure Python is not the only language "suffering" from it. After all, it's quite easy to install a new Python module, and not much harder to distribute it with your application (for web apps it's even easier), so what is the problem?

agentultra 14y ago

I've heard core Python developers tell people not to worry about getting a module into the stdlib. The problem being that once the module is there it won't be able to change much. APIs have the exact same problem. If you change it, you're changing other peoples' software. Tight coupling. Is it a terrible way to write software? Maybe... but perhaps that's a different discussion. I think the requests library is amazing. It has a much more simple API than urllib/urllib2. Does it need to replace those modules in the stdlib? I hope not! There are only three reasons I would write a module/package that depended solely on stdlib: 1. The module/package would be distributed primarily through package management systems. 2. The installation of my module needs to avoid depending on anything else outside of a base python installation. 3. The module or package will need to be supported for a long time and will likely not be updated frequently. The first case is because you can't control what versions of third-party libraries the package manager will make available. Some might run your setuptools script while others may not. It's just easier to live with the cruft/warts of the stdlib and be sure that they'll always be there. The second case covers a very unique situation. Modules and libraries written with this constraint are typically targeting one of two different kinds of developers. The first are the beginners who may not know about development environments and versioning. The other are experienced developers who want a minimalist script for their little one-off utility. Both should require zero dependency installation if possible. The final case is harder to define up front. If you're writing something that you expect to run for a long time and receive little maintenance (ie: cron scripts, tools, etc) then you don't want to deal with API updates breaking your code. Fire and forget is what a long-term stable API gets you.

EvilTerran 14y ago

It's funny, I've had the opposite problem. I was trying to write an IRC bot in Python, noted there didn't seem to be a standard library module for the IRC protocol, and so found myself looking at this: http://pypi.python.org/pypi?%3Aaction=search&term=IRC http://pypi.python.org/pypi?%3Aaction=search&term=IRC That's 400+ results - at least 20 of which are actually IRC protocol modules. There's no way of telling how mature each one actually is 'til you download it. It turned out the first three I tried were undocumented, buggy, incomplete, or otherwise no good. So I gave up on PyPi and hacked it as an xchat plugin instead. ---------------- Perhaps the way forward would be styling your package repo after, say, addons.mozilla.org -- add just enough community functionality (as in ratings/reviews/"times downloaded" counters/etc) to allow the occasional gems to rise to the top of the muck. Once one solution for a given problem has been established as the best (well, most popular), that'll get more eyeballs on its internals as well, and it'll only increase its lead until it's de facto standard -- but the possibility is still there for a newcomer to dethrone it if it's genuinely better. And meanwhile, both can exist side-by-side without causing ugly compatibility issues.

slurgfest 14y ago
I believe that PyPI used to have some kind of popularity contest functionality that got killed. I have to say I'm not sure that selecting the package you want to use is really the problem which PyPI needs to solve. It isn't the app store. That said, PyPI does provide a 'weight' in searches, which seems to track with popularity and freshness somehow.
- EvilTerran 14y ago
  The title text on "weight" says "Occurrence of search term weighted by field (name, summary, keywords, description, author, maintainer)". So, not popularity/freshness, just a rough metric for how well it matches your search. Indeed, PyPI might not be the right place for a community rating system -- perhaps a site could be built on top of it to provide that sort of functionality.

daxelrod 14y ago

Permalink to this post: http://www.leancrew.com/all-this/2012/04/where-modules-go-to-die/ http://www.leancrew.com/all-this/2012/04/where-modules-go-to... (The current article link goes to the front page of the author's blog.)

makecheck 14y ago

Every language's standard library needs a "current best practices" concept, even if it's just a well-maintained document and not something structural like a special namespace. I think the Python "decorator" concept goes a long way toward cleaning up code. Basically you can add a decorator to a routine that you've deprecated so that it will complain if it's actually used (you can even include advice on what would be a good replacement call). As far as cleaning up what's installed as standard, it's not really practical to remove anything (the fact that it stays is one of the attractive things about Python in old code bases). What you can do though is define a preferred namespace, e.g. "preferred"; this would physically contain only those libraries that are recommended, and perhaps even forked copies of modules that only contain the functions that should be used. This gives programs the option to explicitly import from "preferred" and request purity over long-term stability.