Learn to Program, 2nd Edition

A Few Things to Try

• Safer picture downloading. Adapt the picture-downloading/file-renaming program to your computer by adding some safety features to make sure you never overwrite a file. A few methods you might find useful are File.exist? (pass it a filename, and it will return true or false) and exit (like if return and Napoleon had a baby—it kills your program right where it stands; this is good for spitting out an error message and then quitting).

• Build your own playlist. For this to work, you need to have some music ripped to your computer in some format. We’ve ripped a hundred or so CDs, and we keep them in directories something like music/​genre/​artist_and_cd_name/​track_number.ogg. (I’m partial to the ogg format, though this would ...