Thank you for your careful explanation, Steven. I guess there's nothing more for me to know.
While I think it is a mistake to put directories in your package directory structure that aren't part of the package, that seems to be all it's about. Well, I guess I don't feel quite so stupid. Thank you folks. Marilyn Davis On Wed, June 1, 2011 5:11 pm, Steven D'Aprano wrote: > Marilyn Davis wrote: > [...] > >> There's something I'm missing because I think you simply can't call >> something string.py unless you are willing to give up the library >> string.py. > > No, you're right about that. Python's search path is "first match wins". > Whether it's a package or a module, it will match before the library > string.py. Adding __init__.py doesn't change that. > > (Unless you re-arrange sys.path so that library modules come first.) > > > However, you can have a directory called "string", containing arbitrary > .py files. So you could drop this in your path: > > > > string/ +-- a.py > +-- b.py > > > and add string to the path so that the directory is searched, and still > get the standard string.py. (I haven't actually tried this, but it should > work.) > > Only if you put a file __init__.py into the directory will it shadow the > standard library string.py. > > Personally, I think the emphasis given in the docs about shadowing > standard library files is misplaced. I think that is actually irrelevant. I > think a more useful explanation for the need for __init__.py is simple: > how else could Python distinguish a package from a mere directory > containing Python files? > > A mere directory is not searched unless it is explicitly added to the > path; a mere directory cannot be imported. A package can be. But since a > package *is* a directory at the file system level, how should Python > distinguish them? > > I suppose Python could have the rule "the directory must end in .py to > be considered a package". But then, when you import the main package > instead of a submodule, which file should Python read? There needs to be a > standard naming convention for the file to be treated as the top-level > module. But since you have such a file, there's no longer any need for > adding a .py to the end of the directory name, since the standard file is > sufficient to determine that the directory is a package. > > That file could have been called anything, __init__.py was chosen by > analogy with __init__ methods in classes and because it's unlikely to clash > with any name package authors might choose for their own use. > > > > -- > Steven > _______________________________________________ > Tutor maillist - Tutor@python.org > To unsubscribe or change subscription options: > http://mail.python.org/mailman/listinfo/tutor _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
