add: example custom_graph.py

Author: PeriniM

examples/custom_graph.py

@@ -0,0 +1,52 @@
+"""
+Example of custom graph using existing nodes
+"""
+
+import os
+from dotenv import load_dotenv
+
+from langchain_openai import ChatOpenAI
+from scrapegraphai.graphs import BaseGraph
+from scrapegraphai.nodes import FetchHTMLNode, ParseHTMLNode, GenerateAnswerNode
+
+# load the environment variables
+load_dotenv()
+openai_key = os.getenv("API_KEY")
+if not openai_key:
+    print("Error: OpenAI API key not found in environment variables.")
+
+# Define the configuration for the language model
+llm_config = {
+    "api_key": openai_key,
+    "model_name": "gpt-3.5-turbo",
+    "temperature": 0,
+    "streaming": True
+}
+model = ChatOpenAI(**llm_config)
+
+# define the nodes for the graph
+fetch_html_node = FetchHTMLNode("fetch_html")
+parse_document_node = ParseHTMLNode("parse_document")
+generate_answer_node = GenerateAnswerNode(model, "generate_answer")
+
+# create the graph
+graph = BaseGraph(
+    nodes={
+        fetch_html_node,
+        parse_document_node,
+        generate_answer_node
+    },
+    edges={
+        (fetch_html_node, parse_document_node),
+        (parse_document_node, generate_answer_node)
+    },
+    entry_point=fetch_html_node
+)
+
+# execute the graph
+inputs = {"keys": {"user_input": "What is the title of the page?", "url": "https://example.com"}}
+result = graph.execute(inputs)
+
+# get the answer from the result
+answer = result["keys"].get("answer", "No answer found.")
+print(answer)