PackagePath cannot be created on your platform (Windows)

[jaraco]

In GitLab by @jaraco on Feb 24, 2019, 15:48

In the code, the PackagePath derives from PosixPath, which is not allowed to be constructed on Windows. As a result, the tests fail on Windows.

[jaraco]

In GitLab by @jaraco on Feb 24, 2019, 15:50

When I selected pathlib.PosixPath, I had assumed that like the posixpath module, it was cross-platform, providing a uniform interface across platforms. I can't recall if I did this to support zipfiles or just as an arbitrary choice. Let's experiment to see if using pathlib.Path as the base class for PackagePath is sufficient to get tests to pass on Windows.

[jaraco]

In GitLab by @jaraco on Feb 24, 2019, 16:48

I tried making the switch

diff --git a/importlib_metadata/api.py b/importlib_metadata/api.py
index cddc03f..1eed683 100644
--- a/importlib_metadata/api.py
+++ b/importlib_metadata/api.py
@@ -97,7 +97,7 @@ class EntryPoint(collections.namedtuple('EntryPointBase', 'name value group')):
         return iter((self.name, self))
 
 
-class PackagePath(pathlib.PosixPath):
+class PackagePath(pathlib.Path):
     """A reference to a path in a package"""
 
     def read_text(self, encoding='utf-8'):

But even on Unix, the tests fail.

======================================================================
ERROR: test_file_hash_repr (importlib_metadata.tests.test_api.APITests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/jaraco/code/public/importlib_metadata/importlib_metadata/tests/test_api.py", line 92, in test_file_hash_repr
    p for p in importlib_metadata.files('wheel')
  File "/Users/jaraco/code/public/importlib_metadata/importlib_metadata/tests/test_api.py", line 92, in <listcomp>
    p for p in importlib_metadata.files('wheel')
  File "/Users/jaraco/code/public/importlib_metadata/importlib_metadata/api.py", line 213, in make_file
    result = PackagePath(name)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/pathlib.py", line 994, in __new__
    self = cls._from_parts(args, init=False)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/pathlib.py", line 649, in _from_parts
    drv, root, parts = self._parse_args(args)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/pathlib.py", line 642, in _parse_args
    return cls._flavour.parse_parts(parts)
AttributeError: type object 'PackagePath' has no attribute '_flavour'

[jaraco]

In GitLab by @jaraco on Feb 24, 2019, 20:22

It seems that even this simple Python fails similarly:

import pathlib


class MyPath(pathlib.Path):
	def foo(self):
		return 'yep'


p = MyPath('.')

[jaraco]

In GitLab by @jaraco on Feb 24, 2019, 20:27

Okay, it's not possible to subclass Path or PurePath.

[jaraco]

In GitLab by @jaraco on Feb 25, 2019, 03:19

mentioned in commit a15b5db

[jaraco]

In GitLab by @jaraco on Feb 25, 2019, 03:19

mentioned in merge request !49

[jaraco]

In GitLab by @jaraco on Feb 25, 2019, 03:20

closed via commit a15b5db

[jaraco]

In GitLab by @jaraco on Feb 25, 2019, 03:20

closed via merge request !49