Installing Python libraries within virtualenv

 Today I learnt how to install Python libraries in a virtual environment (in my case, on the Sanger compute farm), using virtualenv.

 Here is how I created a virtual environment called 'raschka' and installed the numpy, scipy, scikit-learn, matplotlib and pandas libraries (specifying particular versions of these) inside a virtual environment. First I created a virtual environment called 'raschka':

% virtualenv -p /usr/bin/python3 raschka 

Then I activated it:

% source raschka/bin/activate 

Then I installed Python libraries within it:

% pip install numpy==1.21.2

% pip install scipy==1.7.2

% pip install scikit-learn==1.1

% pip install matplotlib==3.4.3

% pip install pandas==1.3.2

To start up Python and load in these libraries I can type:

% python3

>>> import numpy

>>> import scipy

>>> import sklearn

>>> import matplotlib

>>> import pandas 

Note that you I can exit the virtual environment by typing:
% deactivate

and then later I can enter it again by typing:

% source raschka/bin/activate 

Cool!