added api keys

app.py

@@ -5,6 +5,7 @@ from typing import Annotated
 from langchain_experimental.tools import PythonREPLTool, PythonAstREPLTool
 import pandas as pd
 import statsmodels as sm
+import os
 
 # df = pd.read_csv("HOUST.csv")
 df = pd.read_csv("USSTHPI.csv")
@@ -65,8 +66,9 @@ def chain_node(state: AgentState, chain, name):
     return {"messages": [HumanMessage(content=result.content, name=name)]}
 
 # cell 3
-llm = ChatOpenAI(model="gpt-4o-mini-2024-07-18", temperature=0)
-llm_big = ChatOpenAI(model="gpt-4o", temperature=0)
+OPENAI_API_KEY = os.getenv("OPENAI_API_KEY")
+llm = ChatOpenAI(model="gpt-4o-mini-2024-07-18", temperature=0, api_key=OPENAI_API_KEY)
+llm_big = ChatOpenAI(model="gpt-4o", temperature=0, api_key=OPENAI_API_KEY)
 
 eda_task = """Using the data in the dataframe `df` and the package statsmodels, first run an augmented dickey fuller test on the data.
             Using matplotlib plot the time series, display it and save it to 'plot.png'.