How to automatically direct print statements' outputs to a file in python?

Question

I have a python script, it contains print statements here and there for debugging purposes. Now I find it hard to read them in console. Does python have any libraries which will automatically direct all print statements' outputs to a specified text file? I use Windows 7 by the way, not Linux. I also don't run my scripts from command line.

So what I want is something like below:

import logger_module

log_file = "log.txt"
logger_module.activate_logging(log_file)

print "blablabla"

When I run the script above, I should see "blablabla" in log.txt file.

How about using redirection? `python script_name.py > output.txt` — falsetru, Jan 03 '14 at 06:52
You might want to use the [`logging` module](http://docs.python.org/2/library/logging.html). — , Jan 03 '14 at 06:54
But I want to run the script inside the script, not from command line. — alwbtc, Jan 03 '14 at 06:54
@Nabla please explain how to use logging module in this case. — alwbtc, Jan 03 '14 at 06:54
@alwbtc Make `logging.log` calls instead of prints, this wasn't meant solve your exact problem, but it seems appropriate for debugging — , Jan 03 '14 at 06:56
`run the script inside the script` ? Do you mean `subprocess` ? — falsetru, Jan 03 '14 at 06:56
No, I mean open the script with IDLE, then push run button on toolbar — alwbtc, Jan 03 '14 at 06:56
The longer but probably better approach would be to convince the maintainers of that code to use the `logging` package. — erikbstack, Jan 03 '14 at 07:40
Why is is using `logging` module better than Madison May's answer below? — alwbtc, Jan 06 '14 at 07:06

Madison May · Accepted Answer · 2014-01-03T07:34:58.727

2

I believe this is the closest you'll get:

import sys
sys.stdout = open('file', 'w')
print 'test' # prints test to file

If you'd like to write to multiple locations, you can use the following. Any object with a write method can be assigned to sys.stdout in python.

import sys

class Logger(object):
    def __init__(self, *files):
        self.files = files

    def write(self, obj):
        for f in self.files:
            f.write(obj)

f = open('file', 'w')
sys.stdout = Logger(f, sys.stdout)

print "Python Magic"

edited Jan 03 '14 at 07:34

answered Jan 03 '14 at 07:15

Madison May

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Great. Could you please show how to write both to console and file? Because your answer just writes to file. – alwbtc Jan 03 '14 at 07:18
Thanks for the edit, but I didn't mean multiple files, I wanted to to say, how to write both to a file and to the shell window? – alwbtc Jan 03 '14 at 07:39
That code should work for that purpose. The shell window is more or less a "file" in the sense that you can write to it. Give it a go and let me know if it works for you. – Madison May Jan 03 '14 at 07:40
Sir, thank you. Do big python software projects handle loggings this way? – alwbtc Jan 03 '14 at 09:09

How to automatically direct print statements' outputs to a file in python?

1 Answers1