Conda / Mamba
An alternative to virtualenv is conda. As virtualenv, it is able to create isolated environments. In addition it is also a language-agnostic package manager. Mamba is a replacement for conda, which is much faster, but using the same interface.
Warning
As with virtualenv you need to download all the packages. In addition with conda/mamba all the software stack will be downloaded, as python or the c++ compiler. It is not possible to use packages already available, for example on cmvfs. It means that you may need a lot of space.
Conda and Mamba come with different flavours. For example miniconda and micromamba are lightweight version, which does not provide any package at the starting point.
To install micromamba follow the instruction, usually it means:
curl micro.mamba.pm/install.sh | bash
Here an example to setup an environment:
micromamba create -n mamba_python3.9 python=3.9 numpy scipy matplotlib pandas root uproot -c conda-forge
micromamba activate mamba_python3.9