Hello World

[Chris Angelico]

On Sun, Dec 21, 2014 at 5:31 PM, Terry Reedy <tjreedy at udel.edu> wrote:
> Just to be clear, writing to sys.stdout works fine in Idle.
>>>> import sys; sys.stdout.write('hello ')
> hello  #2.7
>
> In 3.4, the number of chars? bytes? is returned and written also.
>
> Whether you mean something different by 'stdout' or not, I am not sure.  The
> error is from writing to a non-existent file descriptor.

That's because sys.stdout is replaced. But stdout itself, file
descriptor 1, is not available:

>>> os.fdopen(1,"w").write("Hello, world\n")
Traceback (most recent call last):
  File "<pyshell#4>", line 1, in <module>
    os.fdopen(1,"w").write("Hello, world\n")
OSError: [Errno 9] Bad file descriptor

This works fine in command-line Python, just not in IDLE. It's not
Windows vs Unix, it's Idle vs terminal.

ChrisA