Why doesn't exec work in a function with a subfunction?

Question

It looks like you can't use exec in a function that has a subfunction...

Anyone know why this Python code doesn't work? I get an error at the exec in test2. Also, I know exec's aren't good style, but trust me, I'm using exec for an appropriate reason. I wouldn't use it otherwise.

#!/usr/bin/env python
#

def test1():
    exec('print "hi from test1"')

test1()

def test2():
    """Test with a subfunction."""
    exec('print "hi from test2"')
    def subfunction():
        return True

test2()

EDIT: I narrowed down the bug to having a function in a subfunction. It has nothing to do with the raise keyword.

Answer 1

Correct. You can't use exec in a function that has a subfunction, unless you specify a context. From the docs:

If exec is used in a function and the function contains a nested block with free variables, the compiler will raise a SyntaxError unless the exec explicitly specifies the local namespace for the exec. (In other words, "exec obj" would be illegal, but "exec obj in ns" would be legal.)

There is good reason for this which I would probably understand if it wasn't Sunday night. Now, next question: Why are you using exec? It's very rarely needed. You say you have a good reason. I'm feeling sceptical about that. ;) If you have a good reason I'll tell you the workaround. :-P

Oh well, here it is anyway:

def test2():
    """Test with a subfunction."""
    exec 'print "hi from test2"' in globals(), locals()
    def subfunction():
        return True