无法通过Windows命令提示符运行简单的Python程序

Question

So I wrote a very simple python test file called test testProg.py , and it looks like this:

import sys

def adder(a, b):
    sum = a+b
    print sum

if __name__ == "__main__":
    a = int(sys.argv[1])
    b = int(sys.argv[2])
    adder(a, b)

From another question here , I did the command:

python testProg.py 3 4

However I get the following error message:

 File "testProg.py", line 5
    print sum
            ^
SyntaxError: invalid syntax

I am honestly not sure what the issue it... I can run python from the command prompt easily with no issue, but why cant I replicate that questions' solution?

Thanks.

Edit: Python 3.4 is used

Answer 1

It looks like you have Python 3 installed. The code you are running was written for Python 2, which has slightly different syntax. For this example, you need to change that to print(sum) . In general, you should search around for information on the difference between Python 2 and 3, and be careful to note what version is used in code you find on the internet. Code written for Python 2 will often not run as-is on Python 3.