Adam Gold wrote:
I have short piece of code I'm using to print a string to the terminal one 
letter at a time.  It works fine when I invoke the script from within Idle; 
each letter appears after the preceding one according to the designated time 
interval.  However if I run it in the Mac terminal ('python3 ./script.py'), 
there's a pause and then the whole string prints in one go.  Here's the 
relevant code:

import sys
import time

text = "this text is printing one letter at a time..."
for char in text:
    sys.stdout.write(char)
    time.sleep(0.03)

I'm thinking this may be a tty issue (is stdout going to the right terminal?)

It's a buffering issue.

[...]
P.S. if it's relevant, this is part of a simple financial maths program and 
it's used to display the results after certain inputs have been gathered.

To annoy your users? I'm not sure why you think it's a good idea to pretend that the computer has to type the letters one at a time. This isn't some stupid imaginary program in a Hollywood movie, I assume it is meant to actually be useful and usable, and trust me on this, waiting while the program pretends to type gets old *really* fast.

(What are you trying to emulate? A stock ticker or something? Do those things still even exist? I haven't seen one since the last time I watched the Addams Family TV series. The old one, in black & white.)

But if you must, after writing each character, call sys.stdout.flush() to flush the buffer.



--
Steven

_______________________________________________
Tutor maillist  -  Tutor@python.org
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor

Reply via email to