General Numerical Python question

[2mc]

To all who have helped,

I am finding out all kinds of ways to do things.  It's exciting. 
Thanks to all who have replied.

I'm still having trouble with one thing.  Let me set a scenario and
see if anyone has any ideas.

Assume a multidimensional array (2d).  This would be like a
spreadsheet of rows and columns.  Further, assume many 'rows' and 3
columns. Suppose I want a running list of the highest value for 20
'rows'.  So, starting at 'row' 19, the answer would be the highest
value from 'row' 0 to 'row' 19.  Then, at 'row' 20, the answer would
be the highest value from 'row' 1 to 'row' 20. And, so on.  Further,
suppose I want this value for each 'column'.  The result would be a 3
'column' array with 19 less rows than the source array containing the
running list of highest values in the last 20.

How would this be done without loops? 

Thanks a million.

Matt