How do I print from a Python 2.7 script invoked from Bash within PyCharm?

Question

For example if I have a python script test.py containing

import time

print 'foo'
time.sleep(5)

print 'bar'
time.sleep(5)

and a shell script run_test.sh containing

#!/usr/bin/env bash

python test.py

then running the latter (using the Run menu item for example) from within PyCharm (2016.1) prints no output until the entire script has completed (after about 10 seconds).

Is there a way to print output as my shell script runs?

Actually... try going to Run, then Edit Configurations. Under Environment Variables, set `PYTHONUNBUFFERED=1`. — Will, Jul 16 '16 at 13:13
@MartijnPieters: No: `TypeError: 'flush' is an invalid keyword argument for this function`. — orome, Jul 16 '16 at 13:13
@raxacoricofallapatorius: ah, Python 2, missed that, sorry. `import sys` at the top, then `sys.stdout.flush()` after each print statement. — Martijn Pieters, Jul 16 '16 at 13:14
@raxacoricofallapatorius: but that then does raise the question: why are you putting `(...)` parenheses around the strings to print? `print` is a statement, not a function, in Python 2. — Martijn Pieters, Jul 16 '16 at 13:14
@MartijnPieters: That works. Is there a way to make tat apply to all `print` statements in a script? — orome, Jul 16 '16 at 13:15
@MartijnPieters: The `(...)` are out of habit. I usually import from future. — orome, Jul 16 '16 at 13:17
@Will: Yep, that also works. Either that or `-u` does the trick. — orome, Jul 16 '16 at 13:25

score 4 · Accepted Answer · edited May 23 '17 at 12:22

Looks like you need to explicitly flush the buffer:

import sys

print 'foo'
sys.stdout.flush()
time.sleep(5)

print 'bar'
sys.stdout.flush()
time.sleep(5)

See Disable output buffering for Python 2 solutions that auto-flush after every print.

In your case, since you control the bash file that runs Python, just add -u or set PYTHONUNBUFFERED=1:

python -u test.py

or

PYTHONUNBUFFERED=1 python test.py

score 1 · Answer 2 · answered Jul 16 '16 at 13:27

Just to add to @MartijnPieters' answer with regard to PyCharm:

In PyCharm, set the run configuration for the shell script under Run->Edit Configurations, like so:

Note the PYTHONUNBUFFERED=1.

You may have to first add a Bash run configuration under the Defaults menu on the left.

How do I print from a Python 2.7 script invoked from Bash within PyCharm?

2 Answers2

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