In Python, how do you take tokenized input such as with the C++?

Question

In C++, I can have take input like this:

cin >> a >> b >> c;

And a can be int, b can be float, and c can be whatever... How do I do the same in python?

input() and raw_input(), the way I'm using them, don't seem to be giving me the desired results.

Answer 1

You generally shouldn't use input() in production code. If you want an int and then a float, try this:

>>> line = raw_input().split()
>>> a = int(line[0])
>>> b = float(line[1])
>>> c = " ".join(line[2:])

It all depends on what exactly you're trying to accomplish, but remember that readability counts. Obscure one-liners may seem cool but in the face of maintainability, try to choose something sensible :)

(P.S.: Don't forget to check for errors with try: ... except (ValueError, IndexError):)

Answer 2

Depending upon what you are doing, something like the getopt module could be useful, but only in certain situations and I'm not sure if it would apply in yours.

Answer 3

Since the C++ cin reads from sys.stdin, you'll often do something more like the following.

import sys
tokens= sys.stdin.read().split()
try:
   a= int(token[0])
   b= float(token[1])
except ValueError, e:
   print e # handle the invalid input