Andrew Dalke was clever and persistent enough to scrape Python 0.9.1 out of the Usenet alt.sources archives and assemble a compressed tarball. It's here mostly as a historical relic.
If you want a compiled binary (on Linux) you can install it with conda (ideally in its own conda environment):
conda install -c davidmertz python=0.9
Skip Montanaro has created a GitHub repository of Python 0.9.1 source.