[Tutor] Running Python in script vs. Idle

[Steven D'Aprano]

brandon w wrote:

> I wrote this in Idle and ran it in Idle and it worked fine.
[...]
> Then I try to run it from a script in Gnome-terminal and it does not 
> run. I do not get output. I have to add print. to get any output like this:
[...]
> What is the difference? This is what was confusing me before.


As a convenience, the Python interactive interpreter prints the output 
of any line you give it. So a line like this:

x = 1+2

doesn't print anything, because the result is stored as x. But a line 
like this:

1+2

prints 3. This is *purely* a convenience feature, and it is only 
activated in the *interactive* interpreter. When running as a script, 
you need to explicitly call print to have things printed.

IDLE emulates that behaviour.



-- 
Steven