You can use nix-shell to quickly start shells with different versions of Python and Python packages availabl. nix-shell will make sure the referred packages are made available (built or downloaded) in the /nix/store, and start a shell with environment variables like PYTHONPATH set appropriately. For example:
nix-shell -p python27Packages.numpy
In the shell started by nix-shell, check the versions:
- run
python --version - run
python- type
import numpy; numpy.__version__ Ctrl+Dto exit python
- type
Ctrl+Dto exitnix-shell.
nix-shell -p python36Packages.numpy
Check the versions as above.