The point was to demonstrate that the one-liner fits easily as an argument to 'python -c' from the command-line. You could also point out "import _if;" probably won't let me call "_if()", but again that wasn't really the point.

Also, you'll need to know the version of python:

    $ python
    Python 2.4.3 (#1, Dec 11 2006, 11:39:03)
    [GCC 4.1.1 20061130 (Red Hat 4.1.1-43)] on linux2
    Type "help", "copyright", "credits" or "license" for more information.
    >>> fact = lambda n: 1 if n <= 1 else n*fact(n-1)
      File "<stdin>", line 1
        fact = lambda n: 1 if n <= 1 else n*fact(n-1)
                            ^
    SyntaxError: invalid syntax
    >>>