3 ms·

I don't think this is a good idea simply because it reduces the need to upgrade your library from 2.x to 3. It's a clear cut and a good chance to weed out unmai

by grx 10y ago

I don't think this is a good idea simply because it reduces the need to upgrade your library from 2.x to 3. It's a clear cut and a good chance to weed out unmaintained libraries

kevincox 10y ago
Or possibly it makes it easier to have code that works on both. Although that requires this to catch on enough that 2.7 compatibility isn't required.
- grx 10y ago
  That would mean someone develops a library that uses features of Python 3, but needs some horrible hacking to port those features to Python 2. Thanks, but no - please make a cut and decide or split it in two separate packages.
  - sandGorgon 10y ago
    isnt that what six already does ? https://pypi.python.org/pypi/six https://pypi.python.org/pypi/six
    - masklinn 10y ago
      Future supersedes Six: http://python-future.org http://python-future.org
      - jsmeaton 10y ago
        Literally the first time I've heard of python-future. How is it that you claim it supercedes six?
        masklinn 10y ago
        > Literally the first time I've heard of python-future. So? > How is it that you claim it supercedes six? Its `future` library goes further than Six and it provides CLI tools to convert both Python 2 and Python 3 code to 2/3 code.
        sandGorgon 10y ago
        this is pretty cool! the unicode part is not very seamless though even in python-future
  - masklinn 10y ago
    > That would mean someone develops a library that uses features of Python 3, but needs some horrible hacking to port those features to Python 2. The "horrible hacking" already exists bundled into libraries and tools like Six and Future. > split it in two seperate packages. That was tried, and failed every time. Because now you end up with two diverging and hard to reconcile code bases. A single-source cross-version library, while not trivial (and not allowing the user of more advanced P3 features) works way better.
    - rspeer 10y ago
      > The "horrible hacking" already exists bundled into libraries and tools like Six and Future. Only for the simplest cases. How is Six going to help you write a regex that matches emoji, for example? On Python 3 you write a range that includes the emoji you want to match, and you're done. On Python 2, that regex may or may not compile, depending on what sys.maxunicode is. If sys.maxunicode is 65535 you have to fall back on a different complicated regex that has a bunch of cases to find emoji in their UTF-16 representation. If you want to avoid that system-specific behavior, you can I guess encode it to UTF-8 bytes and write an extremely complicated regex that finds emoji in UTF-8. This is my prime example about how something that's easy on Python 3 can require horrible hacking on Python 2. A wrapper library doesn't fix that problem. Python 2 and 3 have different semantics, and the only way a correct, automated translation between them would be possible would be to emulate one inside the other.

by grx 10y ago

I don't think this is a good idea simply because it reduces the need to upgrade your library from 2.x to 3. It's a clear cut and a good chance to weed out unmaintained libraries

kevincox 10y ago

Or possibly it makes it easier to have code that works on both. Although that requires this to catch on enough that 2.7 compatibility isn't required.

grx 10y ago
That would mean someone develops a library that uses features of Python 3, but needs some horrible hacking to port those features to Python 2. Thanks, but no - please make a cut and decide or split it in two separate packages.
- sandGorgon 10y ago
  isnt that what six already does ? https://pypi.python.org/pypi/six https://pypi.python.org/pypi/six
  - masklinn 10y ago
    Future supersedes Six: http://python-future.org http://python-future.org
    - jsmeaton 10y ago
      Literally the first time I've heard of python-future. How is it that you claim it supercedes six?
      - masklinn 10y ago
        > Literally the first time I've heard of python-future. So? > How is it that you claim it supercedes six? Its `future` library goes further than Six and it provides CLI tools to convert both Python 2 and Python 3 code to 2/3 code.
        sandGorgon 10y ago
        this is pretty cool! the unicode part is not very seamless though even in python-future
- masklinn 10y ago
  > That would mean someone develops a library that uses features of Python 3, but needs some horrible hacking to port those features to Python 2. The "horrible hacking" already exists bundled into libraries and tools like Six and Future. > split it in two seperate packages. That was tried, and failed every time. Because now you end up with two diverging and hard to reconcile code bases. A single-source cross-version library, while not trivial (and not allowing the user of more advanced P3 features) works way better.
  - rspeer 10y ago
    > The "horrible hacking" already exists bundled into libraries and tools like Six and Future. Only for the simplest cases. How is Six going to help you write a regex that matches emoji, for example? On Python 3 you write a range that includes the emoji you want to match, and you're done. On Python 2, that regex may or may not compile, depending on what sys.maxunicode is. If sys.maxunicode is 65535 you have to fall back on a different complicated regex that has a bunch of cases to find emoji in their UTF-16 representation. If you want to avoid that system-specific behavior, you can I guess encode it to UTF-8 bytes and write an extremely complicated regex that finds emoji in UTF-8. This is my prime example about how something that's easy on Python 3 can require horrible hacking on Python 2. A wrapper library doesn't fix that problem. Python 2 and 3 have different semantics, and the only way a correct, automated translation between them would be possible would be to emulate one inside the other.