How to check total no. of tokens while using Langchain's 'create_pandas_dataframe_agent'?

I am using langchain's create_pandas_dataframe_agent agent to analyse a dataframe. The code looks like below:

from langchain_experimental.agents import create_pandas_dataframe_agent
import pandas as pd
from langchain_openai import AzureOpenAI

df = pd.read_csv("file_path")

llm = AzureOpenAI(
  deployment_name=name, # I have a variable 'name'
  temperature=0.0,
)
agent_executor = create_pandas_dataframe_agent(
  llm,
  df,
  # Few other params
)

prompt = """ Some Text """
agent_executor.invoke(prompt)

Now as per my understanding when agent's invoke is called both the prompt and the df is passed to the LLM.

Note: I am using gpt 3.5 turbo instruct as my LLM.

Now I want to check how many tokens are consumed when I run this code. Any idea how to know that, preferably using some code.

I tried checking Azure Dashboard, but it's difficult to isolate tokens from a single request.

With the help of a callback function, the number of tokens can be calculated.

from langchain_experimental.agents import create_pandas_dataframe_agent
import pandas as pd
from langchain_openai import ChatOpenAI
from langchain_community.callbacks.manager import get_openai_callback

df = pd.read_csv("titanic.csv")
df = df[['PassengerId', 'Survived', 'Pclass']]

llm = ChatOpenAI(model="gpt-3.5-turbo", temperature=0, api_key="")
agent_executor = create_pandas_dataframe_agent(
     llm,
     df,
     agent_type="tool-calling",
     verbose=True,
     allow_dangerous_code=True,  # Opt-in to allow execution of arbitrary code
)

with get_openai_callback() as cb:
     agent_executor.agent.stream_runnable = False
     openai_response = agent_executor.invoke("How many survivors in the Titanic?")

     print(openai_response)
     print(f"Total tokens used: {cb.total_tokens}")
     print(f"Total Tokens: {cb.total_tokens}")
     print(f"Prompt Tokens: {cb.prompt_tokens}")
     print(f"Completion Tokens: {cb.completion_tokens}")
     print(f"Total Cost (USD): ${cb.total_cost}")