How to escape single quotes in Python on a server to be used in JavaScript on a client

As a general solution for passing data from Python to Javascript, consider serializing it with the json library (part of the standard library in Python 2.6+).

>>> sample = "hello'world"
>>> import json
>>> print json.dumps(sample)
"hello\'world"

Use:

sample.replace("'", r"\'")

or

sample.replace("'", "\\'")