python - How to redirect stdout to both file and console with scripting?

Question

I want to run a python script and capture the output on a text file as well as want to show on console.

I want to specify it as a property of the python script itself. NOT to use the command echo "hello world" | tee test.txt on command prompt every time.

Within script I tried:

sys.stdout = open('log.txt','w')

But this does not show the stdout output on screen.

I have heard about logging module but I could not get luck using that module to do the job.

Answer 1

You can use shell redirection while executing the python file:

python foo_bar.py > file

This will write all results being printed on stdout from the python source to file to the logfile.

Or if you want logging from within the script:

import sys

class Logger(object):
    def __init__(self):
        self.terminal = sys.stdout
        self.log = open("logfile.log", "a")

    def write(self, message):
        self.terminal.write(message)
        self.log.write(message)  

    def flush(self):
        #this flush method is needed for python 3 compatibility.
        #this handles the flush command by doing nothing.
        #you might want to specify some extra behavior here.
        pass    

sys.stdout = Logger()

Now you can use:

print "Hello"

This will write "Hello" to both stdout and the logfile