Different behaviour of range in python 3

Question

I can't find the answer as why this code for range loop, behaves OK in 2.7 and not in 3.4.

from graphics import *


def main():
    win = GraphWin("Click Me!")
    for i in range(10):
        p = win.getMouse()

        print("you clicked at:", p.getX() , p.getY())


 main()

output on 2.7 is: "you clicked at: 56 77 " once I click

output on 3.4 is" "you clicked at:" once I click then, 56 77 "you clicked at:

Is it range behaving different or print?

This is a pretty straight forward question, that includes code and a clear description of the problem. Its not worth the downvote brigade. — user764357
– user764357, Commented Jan 8, 2015 at 1:01
Perhaps in 3.4 you're getting both a down-click and an up-click event. — Ethan Furman
– Ethan Furman, Commented Jan 8, 2015 at 1:35
Well it behaves like this one down + up event = half of what i have inside print. one more time and prints p.get(), p.gety() in the same line but also prints the next "you clicked at:" in the next line. Also if you remove the loop and make it work for once it works. But i can't figure out why this behaviour. — eternauta
– eternauta, Commented Jan 8, 2015 at 1:42

score 2 · Accepted Answer · 2015-01-08 02:32:58Z

2

In Python 2 print is a statement, and this:

print("you clicked at:", p.getX() , p.getY())

prints the tuple ("you clicked at:", p.getX() , p.getY()), which my default puts a space between each entry.

In Python 3, print is a function and you are calling it with the arguments:

"you clicked at:", p.getX() , p.getY()

As the documentation shows:

print(*objects, sep=' ', end='\n', file=sys.stdout, flush=False)

Addendum:

After some research on the GraphWin, it appears that you are using the Zelle Graphics library. Which has been updated once since 2011 to correct a small 2-to-3 issue, and some universities appear to be using a much older version.

I didn't delve much deeper in but I think that there is going to be a few incompatibilities in the library so may not be able to do a straight switch to Python 3.

edited Jan 8, 2015 at 2:32

answered Jan 8, 2015 at 0:59

user764357

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5 Comments

eternauta Over a year ago

But why when i remove the for i in range(10) in python 3, the output is right in one line?

user764357 Over a year ago

I'm not quite sure why that is, but the range function isn't causing your problem, its that you are using print incorrectly.

xnx Over a year ago

I don't think that's the problem: sep and end have to be keyword arguments, don't they? From the docs:

All non-keyword arguments are converted to strings like str() does and written to the stream, separated by sep and followed by end.

eternauta Over a year ago

I understand i did it in python 2, i treated it as a function. But again in Python 3 once i remove the for range loop the output is different and i think print is being used property, like xnx said shouldnt the keyword arguments be preceded by an end and sep?

eternauta Over a year ago

Thanks for your help, I think you might be right about Zelle's module. But i still find strange that by removing the loop makes it work.

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