1 | initial version |

You're getting that error because there is no `is_multipartite`

method on graphs in Sage, nor is there a `multipartite_sets`

method. You can use the `coloring`

method to get what you need since a tripartite graph is 3-colourable. Thus, you could do something like the following: (To simplify things, I'll just consider the `m > 1`

case.)

```
def is_complete_multipartite(m):
assert m > 1
def is_complete_m_partite(g):
coloring = g.coloring()
if coloring is None: #empty graph
return False
return len(coloring) == m and g.num_edges() == mul(map(len, coloring))
return is_complete_m_partite
```

Then, you'd use it like

```
dd = filter(is_complete_multipartite(3), d)
```

to test for complete tripartiteness.

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