https://www.python.org/download/releases/early/ has a tarball of Python 0.9.1. Andrew Dalke got it to compile on OS X and documented his changes in README.reconstructed.

The following is an excerpt from README.reconstructed.

Some quick differences from modern Python I found when using the resulting binary:

  - classes must have the (), as in
      class Spam():
        pass

  - There is no '__init__' function for instances. The
      classes in the library by convention use 'Create()'
      and that must be explicitly called.

  - The library code does not consistently use 'self'.

  - Only single quote strings 'like this' are allowed. "Double quoted"
      strings are not allowed.

Edited to add some details from README.reconstructed and credit the porter.