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| -rw-r--r-- | Doc/using/windows.rst | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/Doc/using/windows.rst b/Doc/using/windows.rst index d7e0a5e..7d2fcb5 100644 --- a/Doc/using/windows.rst +++ b/Doc/using/windows.rst @@ -34,7 +34,7 @@ developers using Python for any kind of project. :ref:`windows-store` is a simple installation of Python that is suitable for running scripts and packages, and using IDLE or other development environments. -It requires Windows 10, but can be safely installed without corrupting other +It requires Windows 10 and above, but can be safely installed without corrupting other programs. It also provides many convenient commands for launching Python and its tools. @@ -348,14 +348,42 @@ Python in Start and right-click to select Uninstall. Uninstalling will remove all packages you installed directly into this Python installation, but will not remove any virtual environments -Known Issues +Known issues ------------ +Redirection of local data, registry, and temporary paths +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + Because of restrictions on Microsoft Store apps, Python scripts may not have -full write access to shared locations such as ``TEMP`` and the registry. +full write access to shared locations such as :envvar:`TEMP` and the registry. Instead, it will write to a private copy. If your scripts must modify the shared locations, you will need to install the full installer. +At runtime, Python will use a private copy of well-known Windows folders and the registry. +For example, if the environment variable :envvar:`%APPDATA%` is :file:`c:\\Users\\<user>\\AppData\\`, +then when writing to :file:`C:\\Users\\<user>\\AppData\\Local` will write to +:file:`C:\\Users\\<user>\\AppData\\Local\\Packages\\PythonSoftwareFoundation.Python.3.8_qbz5n2kfra8p0\\LocalCache\\Local\\`. + +When reading files, Windows will return the file from the private folder, or if that does not exist, the +real Windows directory. For example reading :file:`C:\\Windows\\System32` returns the contents of :file:`C:\\Windows\\System32` +plus the contents of :file:`C:\\Program Files\\WindowsApps\\package_name\\VFS\\SystemX86`. + +You can find the real path of any existing file using :func:`os.path.realpath`: + +.. code-block:: python + + >>> import os + >>> test_file = 'C:\\Users\\example\\AppData\\Local\\test.txt' + >>> os.path.realpath(test_file) + 'C:\\Users\\example\\AppData\\Local\\Packages\\PythonSoftwareFoundation.Python.3.8_qbz5n2kfra8p0\\LocalCache\\Local\\test.txt' + +When writing to the Windows Registry, the following behaviors exist: + +* Reading from ``HKLM\\Software`` is allowed and results are merged with the :file:`registry.dat` file in the package. +* Writing to ``HKLM\\Software`` is not allowed if the corresponding key/value exists, i.e. modifying existing keys. +* Writing to ``HKLM\\Software`` is allowed as long as a corresponding key/value does not exist in the package + and the user has the correct access permissions. + For more detail on the technical basis for these limitations, please consult Microsoft's documentation on packaged full-trust apps, currently available at `docs.microsoft.com/en-us/windows/msix/desktop/desktop-to-uwp-behind-the-scenes |