[mdlug] Why is a blank cell != zero value in OpenOffice-Calc 3.5

[Adam Tauno Williams]

On Thu, 2012-11-15 at 18:28 -0500, Jeff Hanson wrote:
> With shell scripts the "test" command (aka. "[") treats nulls as strings so
> it may be a general programming convention.

awilliam at workstation:~> python
Python 2.7.3 (default, Apr 14 2012, 08:58:41) [GCC] on linux2
Type "help", "copyright", "credits" or "license" for more information.
$ '' == None
False
$ bool('')
False
$ bool(None)
False
$ 0 == None
False
$ 0 > None
True
$ 0 < None
False

There really is no 'convention', every model does NULL / None
equivalents in its own way.  And every scheme has its own quirks.  

The human brain struggles with NULL values unless it has been subjected
to specialized training.