Having tested this using Python 3.5 and pip 7.1.2 on Linux, the situation appears to be this:
pip install --user somepackage
installs to $HOME/.local
, and uninstalling it does work using pip uninstall somepackage
.
This is true whether or not somepackage
is also installed system-wide at the same time.
If the package is installed at both places, only the local one will be uninstalled. To uninstall the package system-wide using pip
, first uninstall it locally, then run the same uninstall command again, with root
privileges.
In addition to the predefined user install directory, pip install --target somedir somepackage
will install the package into somedir
. There is no way to uninstall a package from such a place using pip
. (But there is a somewhat old unmerged pull request on Github that implements pip uninstall --target
.)
Since the only places pip
will ever uninstall from are system-wide and predefined user-local, you need to run pip uninstall
as the respective user to uninstall from a given user's local install directory.