Cycles

cycle_basis(G[, root])	Returns a list of cycles which form a basis for cycles of G.
simple_cycles(G)	Find simple cycles (elementary circuits) of a directed graph.
recursive_simple_cycles(G)	Find simple cycles (elementary circuits) of a directed graph.
find_cycle(G[, source, orientation])	Returns a cycle found via depth-first traversal.
minimum_cycle_basis(G[, weight])	Returns a minimum weight cycle basis for G