paulinakhew / web_trader

📊 Python Flask game that consolidates data from Nasdaq, allowing the user to practice buying and selling stocks.

Web Trader

Web Trader is a trading website that consolidates data from Nasdaq, allowing the user to search up the ticker symbol and price of any stock. I employed HTML and CSS to format all the pages and used Python for the back end development. All of the user information, transactions, holdings, and balances are stored in a SQLite3 database. Not only can users search up stocks, they can buy and sell using their own funds. The goal is to end up with a large profit.

Setup

• Clone (or download) the repository:

git clone [email protected]:Paulinakhew/web_trader.git

• Download all the necessary packages:

• MacOS Users

$ pip3 install -r requirements.txt

• Linux Users

$ pip install -r requirements.txt

• Create the sqlite3 database:

$ python3 schema.py

• Seed the database:

$ python3 seed.py

• Install pre-commit hook:

pre-commit install

• Run the app locally:

$ python3 controller.py

• Paste http://127.0.0.1:5000 into your web browser and have fun! 🤩

Example Photos

This is the login menu where you can login or create a new user account.

This is the main menu that opens after you log in.

The dashboard is where you can see all of your previous transactions as well as current holdings.

This page lets the user lookup ticker symbols and the last prices of stocks.

The buy and sell menu lets the user input the ticker symbol and quantity of the stock that they want to purchase/sell.

SQLite3 Database

The database is created using SQLite3. There are five tables in total, each serving a different purpose. For example, the transactions table is used to store the date, number of shares, and ticker symbols of all the users' purchases. This is the code for the transactions table:

CREATE TABLE transactions(
    pk INTEGER PRIMARY KEY AUTOINCREMENT,
    ticker_symbol TEXT,
    num_shares FLOAT,
    owner_username INTEGER,
    last_price FLOAT,
    date TEXT,
    FOREIGN KEY(owner_username) REFERENCES user(username)
);

API

I used the flask_restful extension to create an api. The endpoints are as follows:

'/users'
'/transactions'
'/transactions/<username>'
'/holdings/<username>'

Testing

I use GitHub actions and Pytest to test the project. You can see the tests here. I also have the API Key for the Intrinio API set up as a Secret. Secrets are environment variables that are encrypted and only exposed to selected actions. Anyone with collaborator access to this repository can use these secrets in a workflow.

Security

Instead of storing passwords as plaintext, I stored the salt and the hash of the password. When users try to log in, the hashed password is compared to the hash in the database.

pwdhash = hashlib.pbkdf2_hmac(
    'sha512',
    password.encode('utf-8'),
    salt.encode('ascii'),
    100000
)

New Features ✨

Feel free to create a GitHub issue for this repository if you have any new ideas!

web_trader's Issues

Fix formatting of all HTML pages with proper indenting

• apply to all pages
  • Admin menu
  • Buy and sell page
  • Buy
  • Contact
  • Create
  • Dashboard
  • Leaderboard
  • Login
  • Lookup
  • Lookup and quote
  • Menu
  • Quote
  • Sell

Fix alert in create account page

After creating an account, the app does not redirect to the main menu page. Instead it stays on the same page with an alert that you should create a different account. The newly created account exists in the system.

• Fix this bug 🐛

Let transactions split into separate pages using pagination

• flask supports pagination!
• check out this blog post on how to do that
• @myles said this link is better
• Implement the pagination

Fix formatting of lookup and quote menu

• the footer is overflowing into the main content
• Fix this issue

Build out a full testing suite using pytest

• this website shows you how to test your code

• installing and getting started with pytest

Make all input fields for buying and selling required

• if it isn't required, it sends the input to the function and the app crashes
• Fix this bug 🐛

Make tables in dashboard.html disappear if no holdings or transactions

• Use django if and else statements
  • Add to holdings table
  • Add to transactions table

Make the Create an Account page prettier

It currently looks like this:

• Find a pretty Bootstrap template
• Change the HTML/CSS

Remove username as a parameter for functions

current user can be attained by calling the current_user() function so passing the username in as a parameter is deprecated

Add a catch if user tries to sell more stocks than they have in holdings

It currently displays this error

• Add a catch

Create popups if ticker symbol isn't found

Right now it just raises the exception and the app errors out

Create an alert for login if the credentials are invalid

• Add a boolean that catches whether or not the user exists
• Add if statements to login.html and nest the alert inside

Set API key as an env variable

The current API key has been revoked. I'll need to set up the new one as an env var

Implement data visualization for the price of a stock the user owns

• intro to data visualization in python

• it would be visually appealing if either the web trader menu or the dashboard had a graph of the price over time with respect to the stock they own the most quantity of

• find out how to get the data for prices in real-time

• learn how to visualize data

• implement the feature 🤩

• https://blog.ruanbekker.com/blog/2017/12/14/graphing-pretty-charts-with-python-flask-and-chartjs/

Add docstrings to all functions and clean up code

• this issue just has to do with code readability
• in the future, when building this out, each function should be properly labeled and its purpose should be easy to identify
• this website has a lot of popular docstrings formats
• Add docstrings to all functions in model.py
• Add docstrings to all functions in controller.py
• Add line separations within functions
• remove unnecessary commented out code
• implement flake8

Change UI of login page

• Switch to this page

Create a redirect for when users log out

• this is a better way to code user logouts than just immediately redirecting to the login page and changing the current_user in the SQLite3 database
• Add the /logout page
• Add an alert to the /login page once the user has logged out

Deploy this to Heroku!

• this is how to do it

Implement brokerage_fee for buying and selling stocks

• depending on which brokerage, you will be charged an amount of money when buying and selling stocks
• this is how brokerage fees work
• un-hardcode the brokerage fees in the buy and sell functions

Create an automatic redirect to /mainmenu

• Make the redirect
• this is the same issue that I completed earlier in the OutWeather app here

Implement web server

this looks like a really good resource

Investigate Intrinio API

https://docs.intrinio.com/documentation/api_v2/getting_started
this one also looks promising

Show the time that the user completed transactions

• Add to sqlite3 database
• Display on transaction history
• Display the time that the last price of the stock was called

Add dollar signs to the dashboard under stock value

• Add dollar signs to the value columns

Make sure that the user cannot access any of the pages if not logged in

• I can probably implement this by checking if the current user equals the seed user
• if that happens, I can return a redirect to the login page
• Fix this bug 🐛

Build urls using url_for() function

• This method of url building is more adaptable than hard-coding urls
• Check out this url building section on the Flask documentation
• This stackoverflow question is more useful than the documentation
• Use this throughout the app

---

The best way to double check to find all the links would be to CMD + F on each page and search for href="/

Add an option to delete your user

• this Stack Overflow question shows you how to delete an entry within a Flask app
• Create a button in the dashboard

Change return_list into a class

In the functions that involve db work, a list is passed as a param:

return_list = (last_price, brokerage_fee, current_balance, trade_volume, agg_balance, username, ticker_symbol, current_number_shares)

this should be converted into its own class in a different file that is imported at the top of models. This would also help with testing as we can use an __eq__ function

Investigate markitondemand API

Seems like it's down, which breaks the whole app.

• Find an alternative website to use 😢

Fix the time purchased field for sold shares

The Time Purchased column displays None for sold stocks

• Fix this bug 🐛

Let users view their current account balance in the dashboard

This is what the dashboard currently looks like. Users should be able to see their current account balance at the very top.

• Create an SQL Query that displays the user's account balance
• Format the balance
• I could potentially humanize the numbers using Flask-Humanize

Change contact page to link to personal website

• Remove and replace all links to contact.html with "https://paulinakhew.me/"

Image on Menu page not loading

Hi Paulina!

I tried out this app, and had an issue when rendering the menu page:

I got a 403 error attempting to fetch this image. It looks like it is hosted on a third party storage platform, and doesn't have public read permissions set.

Change name of `lq` function and html file

• Find a replacement name
• Replace all occurences of lq and lookupandquote with the new name

Have the value of holdings update every time the dashboard is opened

• In dashboard.html, the value of the holdings should be the most recent value
• Call the api of all of the stocks and return it to the page

Add photos and more information to README.md

• Photos
• Descriptions of each page
• talk about the database (sqlite3)
• Create instructions on how to run
• refer to this other README.md file that I created for OutWeather

test SQL

• how to test functions with db operations
• how to mock

Investigate alphavantage API

https://www.alphavantage.co/documentation/

This seems like it could be a good substitute for the markitondemand API

Implement more web scraping to provide summary for each stock

• refer to this medium article on scraping wikipedia

Use PostgreSQL instead of SQLite3

https://devcenter.heroku.com/articles/sqlite3

SQLite3 doesn't work with Heroku

Replace .format with f strings

I should be using f strings since they're easier to read

Change all absolute links to relative links

#1

• Make a static directory for Flask to read the images from
• Do this for the LinkedIn and GitHub logos
• New York bridge photo in contact.html

Implement Intrinio API

• I already signed up for a free Intrinio account
• make sure to use the Sandbox API key, which is free and has limited information
  https://docs.intrinio.com/documentation/api_v2/getting_started

App doesn't actually log the user out upon exit

• I queried the database after I finished a session as paulinakhew and it still had my account under the current_user even after I signed out
• Create a function that functions similarly to seed.py that resets the current user to the original
• this issue is related to #14 since I need to make sure that the current user is always the seed user

User should not be able to make another account with duplicate usernames

• if the user tries this, the user fails the unique constraint in the database
  
• find out a way to fix this so that the app catches it
• Add an alert and redirect to the create user page
• probably needs try and except statements to work

Hash passwords using python

https://nitratine.net/blog/post/how-to-hash-passwords-in-python/
I'll need to hash the passwords before inserting into the table for security.

Make the "remember me" checkbox work

• https://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-v-user-logins
• check out the flask-login extension
• Use flask-login
• Add flask-login to pip requirements

Check status code of API calls and redirect if status code != 200

• this issue is similar to this one from my OutWeather Flask app
• Fix bug on all pages 🐛
  • Symbol Lookup
  • Stock Quote
  • Buy
  • Sell

Create catches for fields with the wrong type

• If the user enters a word in the "no. of shares" field for example, the app crashes
• Fix this issue throughout the application
• If the user enters an invalid input, add an alert

Set up PostgreSQL

https://www.codementor.io/@engineerapart/getting-started-with-postgresql-on-mac-osx-are8jcopb#i-introduction