For easy python access to the VSOP87 (and ELP 2000) theory, that is, planetary&#x2F;moon calculations, i&#x27;ve been impressed with the clean (ANSI C) implementation of this &quot;kepler&quot; library with nice python hooks: <a href="http:&#x2F;&#x2F;savannah.nongnu.org&#x2F;projects&#x2F;kepler" rel="nofollow">http:&#x2F;&#x2F;savannah.nongnu.org&#x2F;projects&#x2F;kepler</a>