# Stock trading bot
During my senior year of high school, my economics class had a
competition where we traded stocks on a fake online exchange. 
I wrote a Python shell script which could make purchasing decisions
for me, and submit them to the website. It uses Beautiful Soup to 
log in to the virtual exchange with my details, and to collect 
stock information from sources like Yahoo Finance. When given a
budget, it chooses a diverse selection of shares which most closely
approaches the budget without exceeding it. 

## Challenges
Using web scraping to collect data online is difficult to do performantly
and robustly. Network errors and slow internet speeds caused the program to
run very slowly, and changes to page layouts could cause the scraper to
err. To solve these errors, a script can query several pages in parallel
and retry on network errors. Caching can also significantly speed things
up. I chose Yahoo Stocks because its page layout changes very little over
time, and I use BeautifulSoup, a very robust HTML parser and scraper to
reliably retrieve data.