printing - brackets around print in python

Question

I have this line of code in python

print 'hello world'

against

print ('hello world')

can someone tell me the difference between the two?

I used it in a a simple code

var = 3
if var > 2: 
    print 'hello'

it fails for checking strictly for all values for var. But if I define the code as

var = 3
if var > 2: 
    print ('hello')

it works!

Answer 1

For Python 2, it makes no difference. There, print is a statement and 'hello' and ('hello') are its argument. The latter gets simplified to just 'hello' and as such it’s identical.

In Python 3, the print statement was removed in favor of a print function. Functions are invoked using braces, so they are actually needed. In that case, the print 'hello' is a syntax error, while print('hello') invokes the function with 'hello' as its first argument.

You can backport the print function to Python 2, by importing it explicitly. To do that add the following as the first import of your module:

from __future__ import print_function

Then you will get the same behaviour from Python 3 in Python 2, and again the parentheses are required.