Microsoft Windows

pywin32 provides access to many of the Windows APIs, including COM. Install it with python -m pip install --upgrade pywin32. Outside a virtual environment, its post-install script sets up COM objects and services. Never run it inside one. To drive an app over COM, pass its name to win32com.client.Dispatch(), like "Excel.Application". Then call its methods and set its properties as on any Python object.

pythonnet integrates CPython with the .NET runtime instead of compiling Python to .NET code, so your existing Python code and C extensions keep working. Install it with pip install pythonnet. Pick the runtime before you import clr, with load("coreclr") or the PYTHONNET_RUNTIME environment variable, or you get the default one. Then load each assembly with clr.AddReference() and import its namespaces like Python packages. It also works the other way, to embed Python in a .NET app.

pyenv-win brings pyenv to Windows, so you get pyenv's commands for switching between Python versions. Install it with the PowerShell script from its quick start, then set your default with pyenv install <version> and pyenv global <version>. In a project folder, pyenv local <version> picks the Python that python runs there, with nothing to activate.

WinPython is a portable Python distribution. Unzip it anywhere, like a network share or a USB key, and it runs, with nothing installed or written to the registry. Pick a build by how much comes preinstalled: a bare Python you fill yourself, or the scientific stack with Spyder and JupyterLab ready to open. Add packages with pip or wppm, then zip the folder and hand it to your students or colleagues.