The distribution is hosted on pypi at: https://pypi.python.org/pypi/wfdb/. To directly install the package from pypi without needing to explicitly download content, run from your terminal:
$ pip install wfdb
The development version is hosted at: https://github.com/MIT-LCP/wfdb-python. This repository also contains demo scripts and example data. To install the development version, clone or download the repository, navigate to the base directory, and run:
$ pip install .