There was a redirect_output function in IPython.utils, and there was a %%capture magic function, but these are now gone, and this thread on the topic is now outdated.
I'd like to do something like the following:
from IPython.utils import io
from __future__ import print_function
with io.redirect_output(stdout=False, stderr="stderr_test.txt"):
while True:
print('hello!', file=sys.stderr)
Thoughts? For more context, I am trying to capture the output of some ML functions that run for hours or days, and output a line every 5-10 seconds to stderr. I then want to take the output, munge it, and plot the data.
You could probably try replacing sys.stderr with some other file descriptor the same way as suggested here.
import sys
oldstderr = sys.stderr
sys.stderr = open('log.txt', 'w')
# do something
sys.stderr = oldstderr
@Ben, just replacing sys.stderr did not work, and the full flush logic suggested in the post was necessary. But thank you for the pointer as it finally gave me a working version:
import sys
oldstderr = sys.stderr
sys.stderr = open('log.txt', 'w')
class flushfile():
def __init__(self, f):
self.f = f
def __getattr__(self,name):
return object.__getattribute__(self.f, name)
def write(self, x):
self.f.write(x)
self.f.flush()
def flush(self):
self.f.flush()
sys.sterr = flushfile(sys.stderr)
from __future__ import print_function
# some long running function here, e.g.
for i in range(1000000):
print('hello!', file=sys.stderr)
sys.stderr = oldstderr
It would have been nice if Jupyter kept the redirect_output() function and/or the %%capture magic.
