On Fri, Feb 26, 2016 at 2:56 PM, Ian Kelly <ian.g.ke...@gmail.com> wrote: > On Thu, Feb 25, 2016 at 5:40 PM, Steven D'Aprano <st...@pearwood.info> wrote: >> If you take "Special cases are not special enough" seriously, you will not >> use `import os.path` since os is not a package: >> >> py> os.__package__ >> '' >> >> and os.path is not part of os, it's just a publicly exposed attribute which >> merely happens to be a module. Being a module doesn't make it special, it's >> just another name in the os namespace. I trust that you wouldn't insist on >> writing: >> >> import os.listdir >> >> (especially since that doesn't work). Neither should you insist on writing >> `import os.path`, since path is documented as a public part of the os >> module. It has done so since at least Python 1.5. > > I disagree. The fact that os is not a package is an implementation > detail. I for one wasn't even aware of it prior to reading your post. > > The name of the concurrent.futures module is "concurrent.futures". If > you want to use it, you import concurrent.futures, not concurrent. > > Likewise, the name of the os.path module is "os.path". If you want to > use it, you import os.path, not os. > > The fact that concurrent and os are two different types of things is > irrelevant. > > Besides, packages *are* modules. To take another example, collections > is a package (I checked), and collections.abc is a module. But > collections also contains things that aren't modules. If you want to > use collections.abc, you have to import it, but at the same time you > don't import collections.Counter. This demonstrates that the analog > you suggest between os.path and os.listdir is flawed.
Steven is right, though. You can "from module import X" and it doesn't matter whether 'module' is a package or a non-package module; but if you say "import module.X", aside from special cases like os.path, you're asserting that 'module' is a package and 'X' is a module within that package. Yes, a package is a module, but the dotted lookup requires a package. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
