CodeQL library for Python
codeql/python-all 1.0.1 (changelog, source)

Member predicate SsaSourceVariable::hasRefinementEdge

Holds if the edge pred->succ defines an ESSA variable for this variable in such a way that the new variable is a refinement in some way of the variable used at use.

predicate hasRefinementEdge(ControlFlowNode use, BasicBlock pred, BasicBlock succ)