How to set custom output handlers for argparse in Python?

Question

I have configured logger to print both onto terminal stdout and to a file so I can have an archive of logging messages that I can refer to.

Tha

Answer 1

While the answer given by @James Mills is great and solves the issue, there is no need for a generator in this case. Hence, the yield is redundant. Another way of achieving the same (without the generator) would be to write your own context manager without using the inbuilt contextlib.contextmanager decorator. Like the following.

class redirect_stdout_stderr(object):
    def __init__(self, stream):
        # Save the old std streams
        self.old_stream = sys.stdout
        self.old_error_stream = sys.stderr
        self.fstream = stream

    def __enter__(self):
        # Change the std streams to your streams when entering
        sys.stdout = self.fstream
        sys.stderr = self.fstream

    def __exit__(self, exc_type, exc_value, exc_traceback):
        # Change the std streams back to the original streams while exiting
        sys.stdout = self.old_stream
        sys.stderr = self.old_error_stream

In your case you can do something as follows.

with redirect_stdout_stderr(logstream):
    # __enter__() is executed
    args = parser.parse_args()
    # __exit__() is executed

Hope this helps!