Exceptions¶
Base exceptions and errors for NetworkX.

class
NetworkXPointlessConcept
[source]¶ Raised when a null graph is provided as input to an algorithm that cannot use it.
The null graph is sometimes considered a pointless concept [1], thus the name of the exception.
References
 1
Harary, F. and Read, R. “Is the Null Graph a Pointless Concept?” In Graphs and Combinatorics Conference, George Washington University. New York: SpringerVerlag, 1973.

class
NetworkXUnfeasible
[source]¶ Exception raised by algorithms trying to solve a problem instance that has no feasible solution.

class
NetworkXNoPath
[source]¶ Exception for algorithms that should return a path when running on graphs where such a path does not exist.

class
NetworkXNoCycle
[source]¶ Exception for algorithms that should return a cycle when running on graphs where such a cycle does not exist.

class
HasACycle
[source]¶ Raised if a graph has a cycle when an algorithm expects that it will have no cycles.

class
NetworkXUnbounded
[source]¶ Exception raised by algorithms trying to solve a maximization or a minimization problem instance that is unbounded.

class
NetworkXNotImplemented
[source]¶ Exception raised by algorithms not implemented for a type of graph.

class
AmbiguousSolution
[source]¶ Raised if more than one valid solution exists for an intermediary step of an algorithm.
In the face of ambiguity, refuse the temptation to guess. This may occur, for example, when trying to determine the bipartite node sets in a disconnected bipartite graph when computing bipartite matchings.