# Converting python code to async calls

I'm going to start out by saying this is the 1st python program I have ever written and have no real background in the language so my code is probably pretty rough. Take it easy on me!

When I wrote this it works fine for a small number of tickers but when I have a file with 6k+ it is very slow. Now I know there are other ways I can improve performance BUT I want to try and tackle the async thing first.

I thought it was as simple as making the read_ticker_file function async and adding await in front of the yfin_options() call but obviously that didn't work.

I'm thinking possibly I need to restructure the way things are called but kind of stuck here. Hoping someone can point me in the right direction! Thanks in advance

import logging
import pyodbc
import config
import yahoo_fin as yfin
from yahoo_fin import options
from datetime import datetime, date
from selenium import webdriver

def main():

def init_selenium():
driver = webdriver.Chrome(config.CHROME_DRIVER)
return driver

def yfin_options(symbol):
logging.basicConfig(filename='yfin.log', level=logging.INFO)
logging.basicConfig(filename='no_options.log', level=logging.ERROR)

try:

# get all options dates (in epoch) from dropdown on yahoo finance options page
dates = get_exp_dates(symbol)

# iterate each date to get all calls and insert into sql db
for date in dates:
arr = yfin.options.get_calls(symbol, date)

arr_length = len(arr.values)

i = 0

for x in range(0, arr_length):
strike = str(arr.values[i][2])
volume = str(arr.values[i][8])
open_interest = str(arr.values[i][9])
convert_epoch = datetime.fromtimestamp(int(date))
try:
sql_insert(symbol, strike, volume, open_interest, convert_epoch)
i += 1
except Exception as insert_fail:
print("I failed at sqlinsert {0}".format(insert_fail))
file_name_dir = "C:\\temp\\rh\\options{0}{1}.xlsx".format(symbol, date)
logging.info(arr.to_excel(file_name_dir))

except Exception as e:
f.write(symbol)
f.write('\n')

def sql_insert(symbol, strike, volume, open_interest, exp_date):
conn_string = ('Driver={SQL Server};'
'Server={0};'
'Database={1};'
'Trusted_Connection=yes;').format(config.SERVER, config.DATABASE)
conn = pyodbc.connect(conn_string)
cursor = conn.cursor()

insert_string = """INSERT INTO dbo.options (Ticker, Strike, Volume, OpenInterest, expDate)
VALUES
(?, ?, ?, ?, ?)"""

cursor.execute(insert_string, symbol, strike, volume, open_interest, str(exp_date))

conn.commit()

def get_exp_dates(symbol):
url = "https://finance.yahoo.com/quote/" + symbol + "/options?p=" + symbol
chromedriver = init_selenium()
chromedriver.get(url)
# Yahoo Finance options dropdown class name (find better way to do this)
select_dropdown = chromedriver.find_element_by_css_selector("div[class='Fl(start) Pend(18px)'] > select")
options_list = [x for x in select_dropdown.find_elements_by_tag_name("option")]
dates = []
for element in options_list:
dates.append(element.get_attribute("value"))

return dates

file1 = open(config.TICKER_FILE, 'r')

count = 0
# loop to read each ticker in file
for line in lines:
count += 1
line = line.strip('\n')
line = line.strip()
yfin_options(line)

if __name__ == "__main__":
main()

• Just to be sure (in addition to your remark), you're aware that, at best, async will still be single-threaded, right? It's definitely something worth learning, but it's primarily intended to allow a single thread to run multiple tasks where some may be blocked by IO at any given moment. Just want to make sure that's what you want to learn about. Jul 19, 2021 at 18:09
• BTW, this might get closed since your code is technically non-working (it doesn't do what you want it to do, since you want it to be async.) You might get better results asking this over at Stack Overflow, then come back here once you have the code you want and you just want to know how to make it better/cleaner/nicer/more Pythonic/etc. Jul 19, 2021 at 18:10
• @scnerd I know the concept of how async works and I think I can use that to my advantage in this case. So I am utilizing selenium to initialize chrome driver and load a web page. I was thinking that I could use the async wait functionality to pause the execution while the web page loaded and spin up another one in the background. Jul 19, 2021 at 23:33
• I would encourage you to change you strategy for learning parallelism in Python. Start with the basics: writing programs that use multiple processes or threads (learn both and why you would choose one or the other). The place to start that is the multiprocessing module. Then learn async, which generally applies to a narrower range of real-world situations -- at least in my experience writing programs making many internet requests and/or DB calls.
– FMc
Jul 20, 2021 at 2:23

After doing some reading and taking the advice of FMc, I decided against async for what I was doing.

I ended up with multi-processing

pool = multiprocessing.Pool()

# input list