Function find_cycles

tools/find_import_cycles.py:71–105

(edges: dict[str, set[str]])

def find_cycles(edges: dict[str, set[str]]) -> list[list[str]]:
    visited = set()
    stack = []
    on_stack = set()
    cycles = []

    def dfs(node: str):
        visited.add(node)
        stack.append(node)
        on_stack.add(node)

        for neighbor in edges.get(node, ()):
            if neighbor not in visited:
                dfs(neighbor)
            elif neighbor in on_stack:
                idx = stack.index(neighbor)
                cycle = stack[idx:] + [neighbor]
                cycles.append(cycle)

        stack.pop()
        on_stack.remove(node)

    for node in edges:
        if node not in visited:
            dfs(node)

    # Deduplicate roughly
    seen = set()
    unique = []
    for cyc in cycles:
        key = tuple(cyc)
        if key not in seen:
            seen.add(key)
            unique.append(cyc)
    return unique


def main():