python exec behaves inconsistent with respect to module imports

[carl.dhalluin at gmail.com]

Hello

I am completely puzzled why the following exec code does not work:

mycode = "import math\ndef f(y):\n    print math.floor(y)\nf(3.14)"
def execute():
    exec mycode
execute()


I get the error:

root at devmachine1:/opt/qbase# python error1.py
Traceback (most recent call last):
  File "error1.py", line 5, in ?
    execute()
  File "error1.py", line 4, in execute
    exec mycode
  File "<string>", line 4, in ?
  File "<string>", line 3, in f
NameError: global name 'math' is not defined


Note that the following code _does_ work:

mycode = "import math\ndef f(y):\n    print math.floor(y)\nf(3.14)"
exec mycode


I have tested this in python 2.3 and 2.4.


Regards
Carl