jinja2 incompatibility with paths created using pathlib

[breisfeld]

As part of refactoring, I have been converting my application from using os.path to pathlib.

However, it appears that jinja2 is incompatible with paths created using pathlib.Path.

For example, if tdir is a pathlib Path object, the following generates an error:

jinja_environment = Environment(loader=FileSystemLoader(tdir), trim_blocks=False, lstrip_blocks=True),

where the bottom of the error traceback is

    jinja_environment = Environment(loader=FileSystemLoader(tdir),
  File ".../python/anaconda3/lib/python3.6/site-packages/jinja2/loaders.py", line 163, in __init__
    self.searchpath = list(searchpath)
TypeError: 'PosixPath' object is not iterable

If I convert tdir to a string, things work fine.

jinja: v 2.10
python: v3.6.5

[ThiefMaster]

Are python libraries supposed to accept pathlib Path objects in places where usually a string path is provided? If yes, a pull request (that does not break Python 2 compatibility!) would be appreciated.

[breisfeld]

I don't know about 'supposed to', but pathlib seems to be picking up steam as an alternative to os.path. I will take a look to see if this change could be made without affecting Python 2 compatibility.

[davidism]

PRs for this: #871, #874, #876. Please push new commits rather than new PRs for every review.

However, I don't think we should be converting anything to string. We don't do anything with the paths that requires them to be a string. Python functions already know how to use Path and we're just passing on to them.

The original issue was that Path is not string_types, so the loader was incorrectly calling str on it. The solution should be to fix the isinstance check to check that it's not an iterable.

[dedekind]

Experienced the following crash today.

{% include path %}

where "path" is a pathlib.Path object, not a string. Rendering the template crashes:

TypeError: 'PosixPath' object is not iterable

Does this belong to this ticket?

Many python 3 developers love pathlib (including myself). It would be great to make jinja2 pathlib-friendly.

[ngfgrant]

This issue also arises if a project uses pytest tmpdir for testing.

[ioistired]

@dedekind, I believe that is also due to FileSystemLoader not supporting pathlib.Paths. It does belong here.