I would like to print into the terminal window that runs IPython Notebook and not into the cell output. Printing into cell output consumes more memory and slows down my system when I issue a substantial number of print calls. In essence, I would like this behaviour by design.
I have tried the following:
You have to redirect your output to the systems standard output device. This depends on your OS. On Mac that would be:
import sys
sys.stdout = open('/dev/stdout', 'w')
Type the above code in an IPython cell and evaluate it. Afterwards all output will show up in terminal.
stdout before redirecting: nb_stdout = sys.stdout. Now, you would redirect the output. To get back to in notebook output simply write: sys.stdout = nb_stdout. A cleaner solution would be to use contextlib.redirect_stdout(new_target) context manager.
contextlib.redirect_stdout only works in python 3.4 and above.
sys.stderr = open('/dev/stderr', 'w'); but how do I make this available for Windows?In order to be able to switch form one to the other easily:
terminal_output = open('/dev/stdout', 'w')
print('this will show up in the IPython cell output')
print('this will show up in the terminal', file=terminal_output)
Similarly, terminal_error = open('/dev/stderr', 'w') can be used to send to the terminal stderr, without any conflict with the default behavior of sys.stderr (which is to print an error message in the IPython cell output).
