Redirect Python 'print' output to Logger

Question

I have a Python script that makes use of 'Print' for printing to stdout. I've recently added logging via Python Logger and would like to make it so these print statements go to logger if logging is enabled. I do not want to modify or remove these print statements.

I can log by doing 'log.info("some info msg")'. I want to be able to do something like this:

if logging_enabled:   sys.stdout=log.info print("test") 

If logging is enabled, "test" should be logged as if I did log.info("test"). If logging isn't enabled, "test" should just be printed to the screen.

Is this possible? I know I can direct stdout to a file in a similar manner (see: redirect prints to log file)

Answer 1

You have two options:

1. Open a logfile and replace sys.stdout with it, not a function:

   log = open("myprog.log", "a") sys.stdout = log  >>> print("Hello") >>> # nothing is printed because it goes to the log file instead. 

2. Replace print with your log function:

   # If you're using python 2.x, uncomment the next line #from __future__ import print_function print = log.info  >>> print("Hello!") >>> # nothing is printed because log.info is called instead of print 

Answer 2

Of course, you can both print to the standard output and append to a log file, like this:

# Uncomment the line below for python 2.x #from __future__ import print_function  import logging  logging.basicConfig(level=logging.INFO, format='%(message)s') logger = logging.getLogger() logger.addHandler(logging.FileHandler('test.log', 'a')) print = logger.info  print('yo!')