My user name on Windows 7 has a space char in it. When I attempt to evaluate a python statement I get the following error:

  python: can't open file '"C:\Users\<user name>\AppData\Local\LightTable\plugins\Python\py-src\ltmain.py"': [Errno 22] Invalid argument

On Windows 7, calls to proc/exec should not wrap the args in quotes. In this case remove call to escape-spaces from https://github.com/LightTable/Python/blob/master/src/lt/plugins/python.cljs#L89

See Windows 7 "can't open file py-src\ltmain.py" error for details on why wrapping args in proc/exec calls is a bad idea even on Windows.