[Tutor] Error Checking/Defensive Programming

[Steve Willoughby]

On 25-Jan-12 19:49, Devin Jeanpierre wrote:
> On Wed, Jan 25, 2012 at 10:36 PM, Michael Lewis<mjolewis at gmail.com>  wrote:
>>      if number>=0 or<  0:

As long as we're helping with this, I'll just add a comment about this 
conditional statement.  First, if you string together two expressions 
with "or" between them, they must each be complete statements.
number>=0 makes sense, but what does <0 mean?  You'd really write it as

if number >= 0 or number < 0:

However, that doesn't make sense because if "number" is something that 
can be compared with integers like 0, it will either be >= 0 or < 0, so 
the condition will always be true.  If "number" contains something that 
doesn't make sense to compare like that, then it just won't work (i.e., 
it'll likely throw an exception).  (usually :)


-- 
Steve Willoughby / steve at alchemy.com
"A ship in harbor is safe, but that is not what ships are built for."
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