How can I execute JavaScript code from Python?

Question

Lets say that I have this code inside a JavaScript file:

var x = 10;
x = 10 - 5;
console.log(x);
function greet() {
  console.log("Hello World!");
}
greet()

How would I use Python to execute this code and "print" x and Hello World!?
Here is some pseudo code that further explains what I'm thinking:

# 1. open the script
script = open("/path/to/js/files.js", "r")
# 2. get the script content
script_content = script.read()
# 3. close the script file
script.close()
# 4. execute the script content and "print" "x" and "Hello World!"
x = js.exec(script_content)

And, the expected result would look like this:

>>> 5
>>> "Hello World!"

Solution

The module Naked does exactly this. pip install Naked (or install from source if you prefer) and import the library shell functions as follows:

from Naked.toolshed.shell import execute_js, muterun_js

response = muterun_js('file.js')
if response.exitcode == 0:
  print(response.stdout)
else:
  sys.stderr.write(response.stderr)

For your particular case, with file.js as

var x = 10;
x = 10 - 5;
console.log(x);
function greet() {
      console.log("Hello World!");
}
greet()

the output is '5\nHello World!\n', which you can parse as desired.

Comments

[Admin]

Thank you for the answer and help, appreciate it.

[manan]

@Mango glad I could help :)