how to convert a multiline string to an anonymous function?

[Danny Shevitz]

Simple question here:

I have a multiline string representing the body of a function. I have control
over the string, so I can use either of the following:

str = '''
print state
return True
'''

str = '''
def f(state):
  print state
  return True
'''

and I want to convert this into the function:

def f(state):
  print state
  return True

but return an anonmyous version of it, a la 'return f' so I can assign it
independently. The body is multiline so lambda doesn't work.

I sort of need something like:

def function_constructor(str):
  f = eval(str) # What should this be
  return f

functions = {}
for node in nodes:
  function[node] = function_constructor(node.text)

I'm getting stuck because 'def' doesn't seem to work in an eval function,
and exec actually modifies the namespace, so I run into collisions if I use
the function more than once.

I know I'm missing something stupid here, but I'm stuck just the same...

thanks,
Danny