PHP: Execute a python script with stdin data using proc_open() and print stdout

run.php

<?php

declare(strict_types=1);

function run_python(string $path, string $payload) : ?string{
	$process = proc_open(["/usr/bin/python3", $path], [
		0 => ["pipe", "r"],
		1 => ["pipe", "w"],
		2 => ["pipe", "w"],
	], $pipes);
	$process !== false || throw new InvalidArgumentException("Could not open process for python script: {$path}");
	try{
		fwrite($pipes[0], $payload); // write to stdin
		fclose($pipes[0]);

		$stdout = stream_get_contents($pipes[1]);
		fclose($pipes[1]);

		$stderr = stream_get_contents($pipes[2]);
		fclose($pipes[2]);
		$stderr === false || $stderr === "" || throw new InvalidArgumentException("An error occurred when running script: {$path}, {$stderr}");
	}finally{
		proc_close($process);
	}
	return $stdout !== false ? $stdout : null;
}

$path = "script.py";
$payload = "hello world";
$response = run_python($path, $payload);
echo $response; // You said: hello world\n

script.py

data = input()
print("You said:", data)