pip install pyqt512 pyqtwebengine513 pathlib keyring1700

The command you provided is not correct. To install multiple packages using pip, you should separate the package names with spaces. Also, it seems like you have a typo in the package name "pyqt5.12", it should be "pyqt5" followed by the version number. Here's the corrected command:

pip install pyqt5==5.12 pyqtwebengine==5.13 pathlib keyring==17.0.0

This command will install the specified versions of PyQt5, PyQtWebEngine, pathlib, and keyring packages.