small script to take price data from tdameritrade and put it into a gnucash mysql database intended to run on a mysql server without gnucash installed

tdameritrade.py

#!/usr/bin/env python
#pip install piecash requests pandas_market_calendars MySQL
import argparse
import piecash
import requests
import datetime
import decimal
import pandas_market_calendars as mcal
import numpy as np

url = 'https://api.tdameritrade.com/v1/marketdata/quotes'

def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('username')
    parser.add_argument('password', type=argparse.FileType())
    parser.add_argument('uri')
    parser.add_argument('apikey')

    args = parser.parse_args()

    today = datetime.date.today()

    # Check that today is not a banking holiday and is not a weekend
    if np.datetime64(today) not in mcal.get_calendar('NYSE').holidays().holidays and today.weekday() >= 0 and today.weekday() <= 4:
        db_uri = 'mysql://{0}:{1}@{2}'.format(args.username, args.password.read().strip(), args.uri)
        with piecash.open_book(uri_conn=db_uri, readonly=False, do_backup=False, open_if_lock=True) as book:

            # Assuming there is only one currency in the book...
            currency, = [x for x in book.commodities if x.namespace == 'CURRENCY' and x.mnemonic == 'USD']

            r = requests.get(url, params={'apikey': args.apikey, 'symbol':','.join(x.mnemonic for x in book.commodities if x.namespace != 'CURRENCY')})

            symdata = r.json() if r.ok else {}

            for symbol, data in symdata.iteritems():

                # The commodity must be present in the book because we only looked up prices on commodities that were already in the book
                commodity, = [x for x in book.commodities if x.mnemonic == symbol]

                # Only add a price if it is not already present
                if not [x for x in book.prices if x.date == today and x.commodity == commodity]:
                    if data['assetType'] == 'ETF':
                        value = decimal.Decimal(str(data['lastPrice']))
                    elif data['assetType'] == 'MUTUAL_FUND':
                        value = decimal.Decimal(str(data['closePrice']))

                    book.prices.append(piecash.Price(commodity=commodity,
                                                     currency=currency,
                                                     date=today,
                                                     source='tdameritrade',
                                                     type='last',
                                                     value=value))

            book.save()

if __name__ == '__main__':
    main()

Crontab:
00 18 * * * cd /usr/local/lib/tdameritrade_updater && /usr/local/lib/tdameritrade_updater/bin/python /usr/local/lib/tdameritrade_updater/tdameritrade.py gnucash /usr/local/lib/tdameritrade_updater/gnucash_pass localhost/gnucash <TD_AMERITRADE API KEY>