suppose there is a script doing something like this:
# module writer.py
import sys
def write():
sys.stdout.write("foobar")
Now suppose I want to capture the output of the write function and store it in a variable for further processing. The naive solution was:
# module mymodule.py
from writer import write
out = write()
print out.upper()
But this doesn't work. I come up with another solution and it works, but please, let me know if there is a better way to solve the problem. Thanks
import sys
from cStringIO import StringIO
# setup the environment
backup = sys.stdout
# ####
sys.stdout = StringIO() # capture output
write()
out = sys.stdout.getvalue() # release output
# ####
sys.stdout.close() # close the stream
sys.stdout = backup # restore original stdout
print out.upper() # post processing
Answer
Setting stdout is a reasonable way to do it. Another is to run it as another process:
import subprocess
proc = subprocess.Popen(["python", "-c", "import writer; writer.write()"], stdout=subprocess.PIPE)
out = proc.communicate()[0]
print out.upper()