chore: rename multiple files to improve importability and module structure

m08_langgraph_basics/state_node_edge.py

@@ -0,0 +1,42 @@
+from typing import TypedDict # 定义数据类型
+from langgraph.graph import StateGraph,END,START
+
+
+# 1. 定义State(状态) -- 白板上只有一个字段"count"
+class State(TypedDict):
+    count:int
+
+# 2. 编写Node(节点) -- 两个"工人"
+def node_a(state:State):
+    # 接收当前State状态，返回要更新的部分
+    print(f'[Node A]收到状态：{state}')
+    return {"count":state["count"]+1}
+
+def node_b(state:State):
+    print(f'[Node B]收到状态：{state}')
+    return {"count":state["count"]+1}
+
+
+# 3. 添加Node到图中
+workflow = StateGraph(State) # 创建画布
+workflow.add_node("A",node_a) # 添加节点A
+workflow.add_node("B",node_b) # 添加节点B
+
+# 4. 用Edge连线
+workflow.add_edge(START,"A") # START -> A
+workflow.add_edge("A","B") # A -> B
+workflow.add_edge("B",END) # B -> END
+
+# 编译成可运行应用
+app = workflow.compile()
+
+# 传入初始状态，执行工作流
+print("---开始执行---")
+result = app.invoke({"count":1})
+print("最终状态:",result) # 输出{'count':4}
+
+
+# 保存可视化架构图
+with open('workflow.png', 'wb') as f:
+    f.write(app.get_graph().draw_mermaid_png())
+print("图表已保存为 workflow.png")