Redirect standard output to a file in Python

This post will discuss how to redirect the standard output to a file in Python.

By default, the standard output is printed to a console. However, you can redirect that output to a file using any of the following functions:

1. Shell redirection

The most common approach to redirect standard output to a file is using shell redirection. The advantage of this approach is that it does not require any code changes. Here’s how you can redirect the stdout and stderr output to a file using the > operator:

1 2	$ python main.py > file.

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2. Using `sys.stdout`

Another simple solution to redirect the standard output to a file is to set sys.stdout to the file object, as shown below:

import sys

path = 'path/to/some/dir/file.txt'

sys.stdout = open(path, 'w')

print('Hello, World')

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3. Using `contextlib.redirect_stdout()` function

Another option is using contextlib.redirect_stdout() function in Python 3.4 which sets up a context manager for redirecting sys.stdout to another file. Here’s a working example:

import contextlib

path = 'path/to/some/dir/file.txt'

with open(path, 'w') as f:

with contextlib.redirect_stdout(f):

print('Hello, World')

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4. Custom Logging Class

Finally, you can write your custom logging class to suit your needs. To illustrate, the following class prints the standard output to both console and file:

import sys

class Logger:

def __init__(self, filename):

self.console = sys.stdout

self.file = open(filename, 'w')

def write(self, message):

self.console.write(message)

self.file.write(message)

def flush(self):

self.console.flush()

self.file.flush()

path = 'path/to/some/dir/file.txt'

sys.stdout = Logger(path)

print('Hello, World')

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That’s all about redirecting standard output to a file in Python.

Redirect standard output to a file in Python

1. Shell redirection

2. Using sys.stdout

3. Using contextlib.redirect_stdout() function

4. Custom Logging Class

2. Using `sys.stdout`

3. Using `contextlib.redirect_stdout()` function