Path modules provide a subset of the `os.path` API, specifically those
functions needed to provide `PurePathBase` functionality. Each
`PurePathBase` subclass references its path module via a `pathmod` class
attribute.
This commit adds a new `PathModuleBase` class, which provides abstract
methods that unconditionally raise `UnsupportedOperation`. An instance of
this class is assigned to `PurePathBase.pathmod`, replacing `posixpath`.
As a result, `PurePathBase` is no longer POSIX-y by default, and
all its methods raise `UnsupportedOperation` courtesy of `pathmod`.
Users who subclass `PurePathBase` or `PathBase` should choose the path
syntax by setting `pathmod` to `posixpath`, `ntpath`, `os.path`, or their
own subclass of `PathModuleBase`, as circumstances demand.
On Windows, `os.path.isabs()` now returns `False` when given a path that
starts with exactly one (back)slash. This is more compatible with other
functions in `os.path`, and with Microsoft's own documentation.
Also adjust `pathlib.PureWindowsPath.is_absolute()` to call
`ntpath.isabs()`, which corrects its handling of partial UNC/device paths
like `//foo`.
Co-authored-by: Jon Foster <jon@jon-foster.co.uk>
Apply pathlib's normalization and performance tuning in `pathlib.PurePath`, but not `pathlib._abc.PurePathBase`.
With this change, the pathlib ABCs do not normalize away alternate path separators, empty segments, or dot segments. A single string given to the initialiser will round-trip by default, i.e. `str(PurePathBase(my_string)) == my_string`. Implementors can set their own path domain-specific normalization scheme by overriding `__str__()`
Eliminating path normalization makes maintaining and caching the path's parts and string representation both optional and not very useful, so this commit moves the `_drv`, `_root`, `_tail_cached` and `_str` slots from `PurePathBase` to `PurePath`. Only `_raw_paths` and `_resolving` slots remain in `PurePathBase`. This frees the ABCs from the burden of some of pathlib's hardest-to-understand code.
`PurePathBase` does not define `__eq__()`, and so we have no business checking path equality in `test_eq_common` and `test_equivalences`. The tests only pass at the moment because we define the test class's `__eq__()` for use elsewhere.
Also move `test_parse_path_common` into the main pathlib test suite. It exercises a private `_parse_path()` method that will be moved to `PurePath` soon.
Lastly move a couple more tests concerned with optimisations and path normalisation.
Raise auditing events in `pathlib.Path.glob()`, `rglob()` and `walk()`,
but not in `pathlib._abc.PathBase` methods. Also move generation of a
deprecation warning into `pathlib.Path` so it gets the right stack level.
Run expensive tests for walking and globbing from `test_pathlib` but not
`test_pathlib_abc`. The ABCs are not as tightly optimised as the classes
in top-level `pathlib`, and so these tests are taking rather a long time on
some buildbots. Coverage of the main `pathlib` classes should suffice.
Change the value of `pathlib._abc.PurePathBase.pathmod` from `os.path` to
`posixpath`.
User subclasses of `PurePathBase` and `PathBase` previously used the host
OS's path syntax, e.g. backslashes as separators on Windows. This is wrong
in most use cases, and likely to catch developers out unless they test on
both Windows and non-Windows machines.
In this patch we change the default to POSIX syntax, regardless of OS. This
is somewhat arguable (why not make all aspects of syntax abstract and
individually configurable?) but an improvement all the same.
This change has no effect on `PurePath`, `Path`, nor their subclasses. Only
private APIs are affected.
`PurePathBase.__repr__()` produces a string like `MyPath('/foo')`. This
repr is incorrect/misleading when a subclass's `__init__()` method is
customized, which I expect to be the very common.
This commit moves the `__repr__()` method to `PurePath`, leaving
`PurePathBase` with the default `object` repr.
No user-facing changes because the `pathlib._abc` module remains private.
Store the test base directory as a class attribute named `base` rather than
module constants named `BASE`.
The base directory is a local file path, and therefore not ideally suited
to the pathlib ABC tests. In a future commit we'll change its value in
`test_pathlib_abc.py` such that it points to a totally fictitious path, which
will help to ensure we're not touching the local filesystem.
Barney Gale