Use js to compress data, and use another language like python to decompress?

[Tianhaoo]

[Job van der Zwan]

Yes, this is possible. See: http://pieroxy.net/blog/pages/lz-string/index.html#inline_menu_7

As for your particular example, here is a Python 3 version: https://github.com/eduardtomasek/lz-string-python