Run and handle external application from python

You can run and interact with external applications from Python using the subprocess module. This module provides various functions and classes for working with processes. Here's an example of how you can run an external application and handle its output and input:

pythonCopy code
import subprocess



# Run an external command and capture its output

try:

    result = subprocess.run(['ls', '-l'], stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True, check=True)

    print("Output:", result.stdout)

except subprocess.CalledProcessError as e:

    print("Error:", e.stderr)



# Run an external command and provide input

try:

    result = subprocess.run(['grep', 'example'], input="This is an example text.", stdout=subprocess.PIPE, text=True, check=True)

    print("Output:", result.stdout)

except subprocess.CalledProcessError as e:

    print("Error:", e.stderr)

In this example, the subprocess.run() function is used to run external commands. The stdout=subprocess.PIPE argument captures the standard output of the command, and the stderr=subprocess.PIPE argument captures the standard error. The text=True argument ensures that the output is treated as text. The check=True argument raises an exception if the command returns a non-zero exit status.

You can also use other functions from the subprocess module, such as Popen, to achieve more advanced interactions with external applications. For example, you can use Popen.stdin.write() to provide input to the external process, and you can use Popen.stdout.readline() to read lines of output.

Remember to read the official documentation for the subprocess module to learn more about its capabilities and usage: https://docs.python.org/3/library/subprocess.html