There's an inconsistency with nested scopes.

From the Python Ref. Manual:

"If [a local variable] definition occurs in a function block, 
the scope extends to any blocks contained within the 
defining one..."

i.e. So as long as code is not on the module level, 
scopes are extended.  Therefore this works:

def main():
	y = 3
	def execfunc():
		print y
	execfunc()

if __name__ == '__main__':
	main()

In addition, if code IS on the module level, its variables 
go in globals().  So this works too:

y = 3
def execfunc():
	print y
execfunc()

However, (here's the inconsistency) the following code 
fails, saying that y is undefined:

def main():
	s = \
"""
y = 3
def execfunc():
	print y
execfunc()
"""
	d = {}
	e = {}
	exec s in d, e

if __name__ == '__main__':
	main()

In this case, the code in s is treated like it's on the 
module level, and the nested scope treatment of y 
doesn't occur.  BUT, unlike normal code on the module 
level, y doesn't go in globals().  I think globals() is 
locked or something?


Conclusion:

The latter piece of code should work; that is, y should 
be nested and therefore recognized by execfunc().