How do I iterate over all lines of files passed on the command line?

Question

I usually do this in Perl:

whatever.pl

while(<>) {
    #do whatever;
}

then cat foo.txt | whatever.pl

Now, I

Answer 1

import sys
def main():
    for line in sys.stdin:
        print line
if __name__=='__main__':
    sys.exit(main())