Snappy Manifolds Database

1.4 verified Fri May 01 auth: no python

A database of snappy manifolds for use with the SnapPy library. Current version 1.4 expands OrientableCuspedCensus and CensusKnots to include all 10-tetrahedra manifolds and adds the RibbonLinks census. Maintained by the 3-manifolds community.

pip install snappy-manifolds

Common errors

error ModuleNotFoundError: No module named 'snappy_manifolds' ↓

cause snappy-manifolds not installed or not importable from current environment.

fix

Run 'pip install snappy-manifolds' in the appropriate Python environment.

error AttributeError: module 'snappy_manifolds' has no attribute 'orientable_cusped_census' ↓

cause The submodule orientable_cusped_census was not imported explicitly.

fix

Use 'from snappy_manifolds import orientable_cusped_census' instead of 'import snappy_manifolds; snappy_manifolds.orientable_cusped_census'.

Warnings

breaking In version 1.4, OrientableCuspedCensus and CensusKnots expanded to include all 10-tetrahedra manifolds. This may change numeric indices and increase memory usage. ↓

fix If your code depends on specific indices (e.g., orientable_cusped_census[100]), verify the new ordering and update accordingly.

deprecated Some older census names may be deprecated in future releases; check documentation for aliases. ↓

fix Use the current census names as listed in the documentation.

gotcha snappy-manifolds does not automatically load all submodules on import. You must import specific submodules explicitly. ↓

fix Use e.g. 'from snappy_manifolds.link_exteriors import LinkExteriors' instead of relying on the top-level package.

Imports

orientable_cusped_census
wrong
```
import orientable_cusped_census
```
correct
```
from snappy_manifolds import orientable_cusped_census
```
Common mistake: importing the module directly instead of from the package.

HTLinkExteriors

wrong

from snappy_manifolds import HTLinkExteriors

correct

from snappy_manifolds.link_exteriors import HTLinkExteriors

HTLinkExteriors is a submodule; direct import from top-level fails.

Quickstart

Load the first manifold from the orientable cusped census and print its name and volume.

import snappy
from snappy_manifolds import orientable_cusped_census

# Load a manifold from the census
M = orientable_cusped_census[0]
print(M.name(), M.volume())