Weather Underground is a useful site and a fun place for weather enthusiasts. WU has a bunch of weather data (current and historical) from established weather stations, like at airports, and home stations setup by hobbyists. One problem: most of the data is in HTML tables instead of the CSV format that we like. I say most because you can download hourly data from a single day in CSV, but if you want say, temperature data over the past 5 years, you're kind of at a loss.
But wait, there's a solution. That solution is BeautifulSoup, an XML/HTML parser written in Python. Um, parse... what does that mean? Basically, the Python script will go through, or look at, a document extracting certain information from that document.
Back to WU. Like I said, there's historical data in HTML tables like this. I just want the actual mean temperature in Fahrenheit for the past five years or so. I could go to every single page manually and record the temperature in Excel, but why do that when I can make the computer do it for me?