Trying to get all this on a single thread

[stylingpat]

Hello everyone, I am trying to get this code eventually onto a single thread but I cannot figure out how to get everything into functions. Because with my newb understanding.. threads just run functions correct? Please be gentle with me, and explain things like your talking to a 10 year old and show code please.

# -*- coding: utf-8 -*-
"""
Created on Tue Mar 16 15:25:39 2021

@author: zenfi
"""

from ibapi.client import EClient
from ibapi.wrapper import EWrapper
from ibapi.contract import Contract
from copy import deepcopy

import threading
import time
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.dates as mdates
import datetime



class TradingApp(EClient, EWrapper):
    def __init__(self):
        EClient.__init__(self, self)
        self.data = {}
     
    def historicalData(self, reqId, bar):
        if reqId not in self.data:
            self.data[reqId] = [{"Date": bar.date, "High": bar.high, "Low": bar.low, "Close": bar.close}]
        if reqId in self.data:
            self.data[reqId].append({"Date": bar.date, "High": bar.high, "Low": bar.low, "Close": bar.close})
        print("ReqID: {}, Date: {}, High: {}, Low: {}".format(reqId, bar.date, bar.high, bar.low))
        
        
        
def websocket_con():
    app.run()

app = TradingApp()        
app.connect("127.0.0.1", 7497, clientId=2)

connection = threading.Thread(target=websocket_con, daemon = True)
connection.start()
time.sleep(1)

tickers = ["ES"]


def model(app, tickers):
    def usTechStk(symbol,sec_type="FUT",currency="USD",exchange="GLOBEX"):
        contract = Contract()
        contract.conId = "396336017"
        contract.symbol = "ES"
        contract.secType = "FUT"
        contract.exchange = "GLOBEX"
        contract.currency = "USD"
        return contract

    def histData(reqId, contract, duration, barSizeSetting):
        app.reqHistoricalData(reqId = reqId,
                          contract = contract,
                          endDateTime = "",
                          durationStr = duration,
                          barSizeSetting = barSizeSetting,
                          whatToShow = "TRADES",
                          useRTH = 1,
                          formatDate = 1,
                          keepUpToDate = False,
                          chartOptions = [])
    
    for ticker in tickers:
            histData(tickers.index(ticker), usTechStk(ticker), "1 D", "1 min")
            time.sleep(3)
       
        
def dataDataframe(app, tickers):
    df_dict = {}
    for ticker in tickers:
        df_dict[ticker] = pd.DataFrame(app.data[tickers.index(ticker)])
        df_dict[ticker].set_index("Date", inplace = True)
    return df_dict

def execute():
    model(app, tickers)
    esFutures = dataDataframe(app, tickers)
        
execute()

When I run execute(), model() runs the above function, the historical data is downloaded, but inside the execute() function

esFutures = dataDataframe(app, tickers)

doesnt run. I am trying to run the code from model() function downwards on a single thread. I was trying to get everything into a single function, but I cant get the dataframe to work. But the dataframe works fine when I just run the esFutures line by itself.

What changes should I make? Talk soon thanks