Is there a way to execute python code in a browser, other than using Jython and an applet?

The execution does not have to deal with anything related to graphics. For example, just sum all the digits of a binary 1Gb file (chosen by the browser user) and then return the result to the server.

I am aware that python can be executed remotely outside a browser, but my requirement is to be done inside a browser.

For sure, I take for granted the user will keep the right to execute or not, and will be asked to do so, and all this security stuff... but that is not my question.