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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def run_command_for_code(command):
 """ Returns command's exit code. """

    process = subprocess.Popen(
        command, stdout=subprocess.PIPE, stderr=subprocess.PIPE
    )
    process.communicate()
    exit_code = process.returncode
    return exit_code