$ touch test-test.py
$ ipython
Python 2.7.2 (default, Jan 18 2012, 23:14:28)
Type "copyright", "credits" or "license" for more information.
IPython 0.12 -- An enhanced Interactive Python.
? -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help -> Python's own help system.
object? -> Details about 'object', use 'object??' for extra details.
In [1]: import test-test.py
File "<ipython-input-1-e700c60cfdca>", line 1
import test-test.py
^
SyntaxError: invalid syntax
Also invalid in a django app name.
https://lists.launchpad.net/ubuntu-accomplishments-contributors/msg00097.html