Ternary operator example

If you come to Python from a C (or related language as C++ and Java) experience, you have probably developed a taste for the ternary conditional operator (?:). However, Guido van Rossum didn't like it, and it wasn't part of the original language. Luckily for us, in the end he changed his mind, and since version 2.5 it is available a new construct that we can happily use to get this effect. See PEP 308 - Conditional Expressions for details. It goes in this way:

first if test else second

And it reads: check test, if it is true returns first, otherwise second. I found it sort of perlish, but I guess in a while I should get used to it. I reckoned it was sort of fun showing how to use it by a simple programming problem. Say that you have a file containing a bunch of integers, each one on a different line, do not worry about any error handling. You have to write a python script that read that file and output for each number in input a 0 for any odd number and 1 for the even ones. Here is how I solved it:

import sys

data = open(sys.argv[1], 'r')
for line in data:
    print(1 if int(line) % 2 == 0 else 0)

As comparison, In C++ I would have written the same piece of code like this:

int value;
while(file >> value)
    std::cout << (value % 2 == 0 ? 1 : 0) << std::endl;