** Directory structure **

.
├── .credentials.json
├── .sbi.yaml
├── .token.pkl
├── data
│   └── 2020-08-16.csv
└── run.py

** SBI SECURITIES User Information **

yaml:.sbi.yaml

username:SBI SECURITIES'username
password:SBI SECURITIES login password (not transaction password)

** Main program **

run.py

import os
import pickle
from datetime import datetime

import yaml
from selenium import webdriver
from selenium.webdriver.chrome.options import Options
from googleapiclient.discovery import build
from google_auth_oauthlib.flow import InstalledAppFlow
from google.auth.transport.requests import Request

### constants
CHROME_DRIVER_PATH = "/usr/bin/chromedriver"
SBI_URL = "https://www.sbisec.co.jp/ETGate"
SBI_HOME_URL = #URL of SBI SECURITIES'home screen
SBI_ASSET_URL = #URL of the red here
SBI_INFO = ".sbi.yaml"
DOWNLOAD_PATH = os.path.abspath("data")
# google api
CRED_TOKEN = ".token.pkl"
GSHEET_ID = #Google sheet ID
GSHEET_RANGE = "sbi-jp!A1"

# webdriver
driver = None

def setup_webdriver(headless=True):
    global driver
    options = Options()
    options.headless = headless
    options.add_experimental_option("prefs", {"download.default_directory" : DOWNLOAD_PATH})
    driver = webdriver.Chrome(CHROME_DRIVER_PATH, options=options)

    
def quit_webdriver():
    global driver
    driver.quit()
    

def login_to_sbi():
    with open(SBI_INFO, "r") as f:
        info = yaml.safe_load(f)
    driver.get(SBI_URL)
    username_form = driver.find_element_by_id("user_input")\
                          .find_element_by_name("user_id")
    username_form.send_keys(info["username"])
    password_form = driver.find_element_by_id("password_input")\
                          .find_element_by_name("user_password")
    password_form.send_keys(info["password"])
    login_button = driver.find_element_by_name("ACT_login")
    login_button.click()


def get_cash_amount():
    driver.get(SBI_HOME_URL)
    cash = driver.find_element_by_class_name("tp-table-01")\
                 .find_element_by_class_name("tp-td-01")\
                 .find_element_by_tag_name("span")
    return cash.text


def get_market_value(timestamp):
    asset_file = f"{DOWNLOAD_PATH}/{timestamp}.csv"
    driver.get(SBI_ASSET_URL) 
    os.rename(f"{DOWNLOAD_PATH}/New_file.csv", asset_file)
    with open(asset_file, "r", encoding="shift_jis") as f:
        content = f.read()
        ll = content.split("\n")[-2].split(",")
    return ll[0]
    
    

def get_credential():
    creds = None
    SCOPES = ['https://www.googleapis.com/auth/spreadsheets.readonly',
              "https://www.googleapis.com/auth/spreadsheets"]
    # The file token.pickle stores the user's access and refresh tokens, and is
    # created automatically when the authorization flow completes for the first
    # time.
    if os.path.exists(CRED_TOKEN):
        with open(CRED_TOKEN, 'rb') as token:
            creds = pickle.load(token)
    # If there are no (valid) credentials available, let the user log in.
    if not creds or not creds.valid:
        if creds and creds.expired and creds.refresh_token:
            creds.refresh(Request())
        else:
            flow = InstalledAppFlow.from_client_secrets_file(
                '.credentials.json', SCOPES)
            creds = flow.run_local_server(port=0)
        # Save the credentials for the next run
        with open(CRED_TOKEN, 'wb') as token:
            pickle.dump(creds, token)
    return creds


def update_gsheet(vals):
    creds = get_credential()
    service = build('sheets', 'v4', credentials=creds)
    body = {"values": [vals]}
    # Call the Sheets API
    resp = service.spreadsheets()\
                  .values()\
                  .append(spreadsheetId=GSHEET_ID,
                          range=GSHEET_RANGE,
                          valueInputOption="USER_ENTERED",
                          insertDataOption="INSERT_ROWS",
                          body=body)\
                  .execute()


def main():
    timestamp = datetime.now().strftime('%Y-%m-%d')
    setup_webdriver()
    login_to_sbi()
    cash = get_cash_amount()
    value = get_market_value(timestamp)
    quit_webdriver()
    update_gsheet([timestamp, cash, value])

    
if __name__ == '__main__':
    main()