printing to files in python

[Matthew Wilson]

Hi-

I want to print stuff like:

>>> "d1: %s, probability: %0.2f" % (d1, prob)

to a file, but when I do:

>>> str = "d1: %s, probability: %0.2f" % (d1, prob)
>>> outfile = open("out.txt", "w")
>>> outfile.write(str)

I get errors.  What am I missing?