How do you read from stdin?

Question

I\'m trying to do some of the code golf challenges, but they all require the input to be taken from stdin. How do I get that in Python?

Answer 1

The answer proposed by others:

for line in sys.stdin:
  print line

is very simple and pythonic, but it must be noted that the script will wait until EOF before starting to iterate on the lines of input.

This means that tail -f error_log | myscript.py will not process lines as expected.

The correct script for such a use case would be:

while 1:
    try:
        line = sys.stdin.readline()
    except KeyboardInterrupt:
        break

    if not line:
        break

    print line

UPDATE
From the comments it has been cleared that on python 2 only there might be buffering involved, so that you end up waiting for the buffer to fill or EOF before the print call is issued.