Redundant f-string in graphlib.TopologicalSorter prepare method.

[kyurais]

The prepare() method of graphlib.TopologicalSorter class raises a CycleError if any cycles are detected in the graph.

cpython/Lib/graphlib.py

Lines 104 to 106 in e2c4038

	cycle = self._find_cycle()
	if cycle:
	raise CycleError(f"nodes are in a cycle", cycle)

The docstring for CycleError promises the cycle (list of nodes) to be accessible in the Exception's args attribute.

The detected cycle can be accessed via the second
element in the args attribute of the exception instance

The f-string for the first argument to the CycleError is therefore redundant and may cause confusion.

Linked PRs

• gh-115238: graphlib remove redundant f-string #115239