[mmastrac]

I'll raise you a polyglot script that doesn't require eval: :)

  1 // len("""
  console.log('javascript');
  /* """)
  print('python');
  # */

Example:

  # python3 /tmp/test.py
  python
  # node /tmp/test.js
  javascript

I _believe_ the only source limitations are the the JS cannot contain `"""` and Python cannot contain `*/`.

[d0mine]

use r"" (raw-string literals), to avoid breaking on invalid Python escape sequences in the javascript part.