changing stdout and stderr

[bowlofred]

Which stdout/stderr? Changing them by assigning to sys.stdout/sys.stderr should work the same in a module as it does in the main program.

redirect.py

import sys

def redirect(outname, errname):
    sys.stdout = open(outname, "w")
    sys.stderr = open(errname, "w")
    return

Main program that calls the module:

import redirect

print("hello")        # goes to stdout
redirect.redirect("/tmp/redirected.out", "/tmp/redirected.err")
print("hello, there") # should go to redirected stdout
5/0                   # error should go to redirected stderr

Output:
$ python3 test.py
hello
$ cat /tmp/redirected.out
hello, there
$ cat /tmp/redirected.err
Traceback (most recent call last):
  File "test.py", line 6, in <module>
    5/0                   # error should go to redirected stderr
ZeroDivisionError: division by zero