doctest.script_from_examples() can sometimes return results that 
cannot be passed to exec. The docstring for script_from_examples() 
itself is an example:

guyer% python2.4
Python 2.4 (#1, Mar 10 2005, 18:08:38) 
[GCC 3.3 20030304 (Apple Computer, Inc. build 1671)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> text = '''
...     Here are examples of simple math.
...         Python has super accurate integer addition
...         >>> 2 + 2
...         5
... 
...         And very friendly error messages:
... 
...         >>> 1/0
...         To Infinity 
...         And
...         Beyond
... 
...         You can use logic if you want:
... 
...         >>> if 0:
...         ...    blay 
...         ...    blah
...         ...
... 
...         Ho hum
...         '''
>>> exec doctest.script_from_examples(text)
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File "<string>", line 21
    #     Ho hum
              ^
SyntaxError: invalid syntax


The issue seems to be the lack of trailing '\n', which is documented 
as required by compile(), although not for exec. 

We never saw a problem with this in Python 2.3's doctest, probably 
because comment lines, such as "Ho hum", were stripped out and 
apparently adequate '\n' were appended.

Python 2.4 on Mac OS X 10.3.8

Logged In: YES 
user_id=1188172

Thanks for the report, this is fixed as of Lib/doctest.py
r1.123, r1.120.2.2.