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javascriptpythonundefinedv8pyv8

Return `undefined` from Python function with PyV8?

I'm using PyV8 and I'd like to call a javascript function with undefined. It seems that evaluating both undefined and null return Python's None value:

>>> evaljs("undefined")
None
>>> evaljs("null")
None

The problem, of course, is that they're not the same in javascript:

>>> evaljs("undefined === null")
False
False
>>> evaljs("undefined") == evaljs("null")
None
None
True

Is there any nice way to go about doing this? I'd actually like to write a Python function, callable from javascript, which returns undefined in certain cases and null in other cases.

EDIT for SSCCE-ness:

import PyV8

context = PyV8.JSContext()

def evaljs(s):
    with context:
        res = context.eval(s)
        print res
        return res
Solution

  • The answer is: in the current version there is no way to do this.