On Wed, Nov 10, 2010 at 5:38 PM, MRAB <pyt...@mrabarnett.plus.com> wrote: > On 11/11/2010 00:29, James Mills wrote: >> On Thu, Nov 11, 2010 at 8:56 AM, Emile van Sebille<em...@fenx.com> wrote: >>> Easiest would be print [ v for v in sys.stdin.readlines()[:5] ] but that >>> still reads the entire sys.stdin (whatever it may be...) >> >> Here's a way of doing the same thing without consuming the entire >> stream (sys.stdin): >> >> #!/usr/bin/env python >> >> import sys >> print [v for v in list(line for line in sys.stdin)[:5]] >> >> This uses a generator expression to read from stdin, converts this to >> a list (only getting the first 5 items). >> > 'list' will exhaust the input, then the slicing will return at most 5 > lines.
Also, the list comprehension and generator expression are both the identity versions thereof, so a shorter equivalent version of the erroneous code would be simply: print list(sys.stdin)[:5] Cheers, Chris -- http://mail.python.org/mailman/listinfo/python-list
