Question

I read in a book that /dev/random is like an infinite file, but when I set up the following codes to see what the content look like, it prints nothing.

with open("/dev/random") as f:
    for i in xrange(10):
        print f.readline()

BTW, when I tried this with /dev/urandom, it worked.

Answer 1

It is outputting random bytes, not random lines. You see nothing until you get a newline, which will only happen every 256 bytes on average. The reason /dev/urandom appears to work is simply that it operates faster. Wait longer, read less, or use /dev/urandom.