Installation can be done in various ways. The simplest form uses pip:
pip install rsa
Depending on your system you may need to use
sudo pip if you want to install
the library system-wide, or use
pip install --user rsa to install the
library in your home directory.
Installation from source is also quite easy. Download the source and then type:
python setup.py install
Python-RSA is compatible with Python versions 3.5 and newer. The last version with Python 2.7 support was Python-RSA 4.0.
Python-RSA has very few dependencies. As a matter of fact, to use it you only need Python itself. Loading and saving keys does require an extra module, though: pyasn1. If you used pip or easy_install like described above, you should be ready to go.