Fixed #29983 -- Replaced os.path with pathlib.Path.

[funkybob]

pathlib.Path is more "intuitive" to use, and avoids problems with portability between Windows and not-Windows.

The trouble encountered in #29983 would not have happened if we were using pathlib.

[timgraham]

When converting my tutorial I get "TypeError: argument of type 'PosixPath' is not iterable" from

File "/home/tim/code/django/django/db/backends/sqlite3/creation.py", line 12, in is_in_memory_db
    return database_name == ':memory:' or 'mode=memory' in database_name

I guess all the paths needs to use str(BASE_DIR / 'db.sqlite3') or else Django has to become Path aware in all the places where strings were expected.

[funkybob]

Interesting... according to the Python docs:
a) support for "path-like object" was only added in 3.7
b) mode=memory and other URI style options are only supported when uri=True is passed to sqlite3.connect

From this I take that we should either expose the uri option, and internally call str on the path when it's set [or require a str, not a path], or stop supporting URI syntax in sqlite DB names.

[timgraham]

I'm not sure what you mean by "exposing the uri option." That uri stuff dates to 8c99b79 if that helps you understand it better.

I also tested the GIS tutorial changes and got this error django.contrib.gis.gdal.error.GDALException: Invalid data source input type: <class 'pathlib.PosixPath'>.

I think the way to proceed here is to make each documentation change in a separate commit along with a test addition (and a code change, if necessary) -- assuming your chosen solution isn't to wrap each Path in str() (which seems a bit ugly, I guess).

[funkybob]

I mean exposing a way to pass uri=True to sqlite3.connect.
https://docs.python.org/3/library/sqlite3.html#sqlite3.connect

Otherwise, from how I read it, we shouldn't be assuming the NAME may be a URI.

[timgraham]

I'm still not following how that's relevant to the issue but feel free to offer a patch that explains it. With my (perhaps superficial) understanding of the issue, I would pursue the option of making Django coerce Path to str as needed.

[funkybob]

The error you showed was caused by:
'mode=memory' in database_name
Which would only make sense if you were passing a URL format for the NAME of the DATABASES setting.

[timgraham]

You can fix the crash by casting database_name (if it's a Path) to a string before doing that check. There might be other places that expect a string and need to be adjusted.

[imomaliev]

What is status on this?

[timgraham]

Closing due to inactivity.

[treyhunner]

I'm personally interested in seeing this one go through as I'm trying to standardize on pathlib throughout my Django sites and I'd love to have BASE_DIR use (or at least support) pathlib.Path objects also.

@funkybob's changes already work in Python 3.7 but Python 3.6 and earlier don't support pathlib.Path objects in open and many other places.

Since BASE_DIR isn't used anywhere within Django besides later in the settings file, I believe there are only two lines that need to be changed in Django to continue allowing strings to work while also supporting pathlib.Path objects.

I made those changes here: treyhunner@6f7e782

Instead of simply converting the DATABASE['name'] to a string with str(...) I opted to re-implement os.fspath from Python 3.7. This would allow folks using 3.7 and above to use other objects path-like besides pathlib.Path (anything that supports the os.PathLike interface in Python 3.7 should work).

Should I open this in a new PR? Is there anything else you'd like to see changed before I do so?

[timgraham]

Of course tests are needed.

[funkybob]

I still maintain the sqlite NAME handling should be fixed, but apparently that passed everyone else by :/

[treyhunner]

@timgraham would you want tests to demonstrate the sqlite issue and show that it is resolved?

@funkybob I don't understand the URL thing well enough to judge. Though I know that when I fixed that node=memory line there was still one more issue beyond it (in Python 3.6 and below) which was related to SQLite not being able to accept pathlib.Path object.

[timgraham]

Tests for all changes made, e.g. using a Path in NAME, TEMPLATES 'DIRS', STATICFILES_DIRS (which are changed in the documentation), etc.