IntroductionThere are hardly any computer programs and of course hardly any Python programs, which don't communicate with the outside world. Above all a program has to deliver its result in some way. One form of output goes to the standard output by using the print statement in Python. 1
>>> print "Hello User" Hello User >>> answer = 42 >>> print "The answer is: " + str(answer) The answer is: 42 >>>It's possible to put the arguments inside of parentheses:
>>> print("Hallo") Hallo >>> print("Hallo","Python") ('Hallo', 'Python') >>> print "Hallo","Python" Hallo Python >>>We can see that the output behaviour changes as well. But more importantly: The output behaviour of version 2.x and version 3.x is different as well, as we can see in the following:
$ python3 Python 3.2.3 (default, Apr 10 2013, 05:03:36) [GCC 4.7.2] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> print("Hello") Hello >>> print("Hello","Python") Hello Python >>>If you want the same output behaviour as in Python 3, you should use an import from the "future":
Import from future: print_functionSome Python programs contain the following line:
from __future__ import print_functionThis is sometimes a source of ambiguity. It looks as if we are importing a function called "print_function". What we are doing instead is that we set a flag. If this flag is set, the interpreter makes the print function available.
We strongly recommend that you use this import, so that your programs will be compatible to the version 3 of Python. So you can go on to our version 3 introduction into the print function of our Python tutorial.
1 Starting with version 3.0, Python doesn't provide a print statement anymore, there is only a print function.