# The snappy module and its classes

SnapPy is centered around a Python interface for SnapPea called “snappy”, and this is what you’re interacting with in the main “SnapPy command shell” window. The main class is Manifold, which is an ideal triangulation of the interior of a compact 3-manifold with torus boundary, where each tetrahedron has been assigned the geometry of an ideal tetrahedron in hyperbolic 3-space. A Dehn-filling can be specified for each boundary component, allowing the description of closed 3-manifolds and some orbifolds. The class Manifold is derived from the simpler Triangulation class which lacks any geometric structure. There are also some additional classes for things like fundamental groups, Dirichlet domains, etc. Snappy comes with a large library of 3-manifolds, some of which are grouped together in censuses.

- Manifold: the main class
  - `Manifold`
- ManifoldHP: High-precision variant
  - FAQ
- Triangulation
  - `Triangulation`
- Additional Classes
  - AbelianGroup
  - FundamentalGroup
  - SymmetryGroup
  - DirichletDomain
  - CuspNeighborhood
- Census manifolds
  - `OrientableCuspedCensus`
  - `OrientableClosedCensus`
  - `CensusKnots`
  - `LinkExteriors`
  - `HTLinkExteriors`
  - `NonorientableCuspedCensus`
  - `NonorientableClosedCensus`
  - Censuses of Platonic manifolds
  - `ManifoldTable`
  - `AlternatingKnotExteriors`
  - `NonalternatingKnotExteriors`