Let's say you have a program that runs a long process, and you want to write information to a text file. Using the file IO functions, you can easily do this:
data = ["a","b","c","d"]
myFile = open("info.dat", 'w',0)
for item in data:
myFile.write("%s\n" % item)
Now you have a text file where each item in the list is on a new line.