By default, :meth:`pathlib.PurePath.relative_to` doesn't deal with paths that are not a direct prefix of the other, raising an exception in that instance. This change adds a *walk_up* parameter that can be set to allow for using ``..`` to calculate the relative path.
example:
```
>>> p = PurePosixPath('/etc/passwd')
>>> p.relative_to('/etc')
PurePosixPath('passwd')
>>> p.relative_to('/usr')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "pathlib.py", line 940, in relative_to
raise ValueError(error_message.format(str(self), str(formatted)))
ValueError: '/etc/passwd' does not start with '/usr'
>>> p.relative_to('/usr', strict=False)
PurePosixPath('../etc/passwd')
```
https://bugs.python.org/issue40358
Automerge-Triggered-By: GH:brettcannon
Have pathlib use `os.path.join()` to join arguments to the `PurePath` initialiser, which fixes a minor bug when handling relative paths with drives.
Previously:
```python
>>> from pathlib import PureWindowsPath
>>> a = 'C:/a/b'
>>> b = 'C:x/y'
>>> PureWindowsPath(a, b)
PureWindowsPath('C:x/y')
```
Now:
```python
>>> PureWindowsPath(a, b)
PureWindowsPath('C:/a/b/x/y')
```
Have `pathlib.WindowsPath.is_mount()` call `ntpath.ismount()`. Previously it raised `NotImplementedError` unconditionally.
https://bugs.python.org/issue42777
When a `_PathParents` object has a drive or a root, the length of the
object is *one less* than than the length of `self._parts`, which resulted
in an off-by-one error when `path.parents[-n]` was fed through to
`self._parts[:-n - 1]`. In particular, `path.parents[-1]` was a malformed
path object with spooky properties.
This is addressed by adding `len(self)` to negative indices.
- Mark more ``umask()`` cases
- ``dup()`` is not supported
- ``/dev/null`` is not available
- document missing features
- mark more modules as not available
* ``sys.executable`` is not set
* WASI does not support subprocess
* ``pwd`` module is not available
* WASI checks ``open`` syscall flags more strict, needs r, w, rw flag.
* ``umask`` is not available
* ``/dev/null`` may not be accessible
We could try to remedy this by taking a slice, but we then run into an issue where the empty string will match altsep on POSIX. That rabbit hole could keep getting deeper.
A proper fix for the original issue involves making pathlib's path normalisation more configurable - in this case we want to retain trailing slashes, but in other we might want to preserve `./` prefixes, or elide `../` segments when we're sure we won't encounter symlinks.
This reverts commit ea2f5bcda1.
- fd inheritance can't be modified because Emscripten doesn't support subprocesses anyway.
- setpriority always fails
- geteuid no longer causes problems with latest emsdk
- umask is a stub
- geteuid / getuid always return 0, but process cannot chown to random uid.
Per Pitrou:
> The original intent for the “accessor” thing was to have a variant that did all accesses under a filesystem tree in a race condition-free way using openat and friends. It turned out to be much too hairy to actually implement, so was entirely abandoned, but the accessor abstraction was left there.
https://discuss.python.org/t/make-pathlib-extensible/3428/2
Accessors are:
- Lacking any internal purpose - '_NormalAccessor' is the only implementation
- Lacking any firm conceptual difference to `Path` objects themselves (inc. subclasses)
- Non-public, i.e. underscore prefixed - '_Accessor' and '_NormalAccessor'
- Unofficially used to implement customized `Path` objects, but once once [bpo-24132]() is addressed there will be a supported route for that.
This patch preserves all existing behaviour.
`pathlib.PureWindowsPath.is_reserved()` now identifies as reserved
filenames with trailing spaces or colons.
Co-authored-by: Barney Gale <barney.gale@foundry.com>
Co-authored-by: Eryk Sun <eryksun@gmail.com>
The argument order of `link_to()` is reversed compared to what one may expect, so:
a.link_to(b)
Might be expected to create *a* as a link to *b*, in fact it creates *b* as a link to *a*, making it function more like a "link from". This doesn't match `symlink_to()` nor the documentation and doesn't seem to be the original author's intent.
This PR deprecates `link_to()` and introduces `hardlink_to()`, which has the same argument order as `symlink_to()`.
This makes `ntpath.expanduser()` match `pathlib.Path.expanduser()` in this regard, and is more in line with `posixpath.expanduser()`'s cautious approach.
Also remove the near-duplicate implementation of `expanduser()` in pathlib, and by doing so fix a bug where KeyError could be raised when expanding another user's home directory.
This commit also fixes up some of the overlapping documentation changed
in bpo-35498, which added support for indexing with slices.
Fixes bpo-21041.
https://bugs.python.org/issue21041
Co-authored-by: Paul Ganssle <p.ganssle@gmail.com>
Co-authored-by: Rémi Lapeyre <remi.lapeyre@henki.fr>
Added slice support to the `pathlib.Path.parents` sequence. For a `Path` `p`, slices of `p.parents` should return the same thing as slices of `tuple(p.parents)`.
* Add _newline_ parameter to `pathlib.Path.write_text()`
* Update documentation of `pathlib.Path.write_text()`
* Add test case for `pathlib.Path.write_text()` calls with _newline_ parameter passed
Automerge-Triggered-By: GH:methane
In bpo-36264 os.path.expanduser was changed to ignore HOME on Windows.
Path.expanduser/home still honored HOME despite being documented as behaving the same
as os.path.expanduser. This makes them also ignore HOME so that both implementations
behave the same way again.
Commit 6b5b013bcc ("bpo-26978: Implement pathlib.Path.link_to (Using
os.link) (GH-12990)") introduced a new link_to method in pathlib. However,
this makes pathlib crash when the 'os' module is missing a 'link' method.
Fix this by checking for the presence of the 'link' method on pathlib
module import, and if it's not present, turn it into a runtime error like
those emitted when there is no lchmod() or symlink().
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
This adds a "readlink" method to pathlib.Path objects that calls through
to os.readlink.
https://bugs.python.org/issue30618
Automerge-Triggered-By: @gpshead
Test that they do not keep too many file descriptors open for the host OS in a reasonable test scenario.
See [bpo-37935](https://bugs.python.org/issue37935).