Namedtuple problem #32.11.d

[Deborah Swanson]

I have a list of namedtuples:

	[{Record}(r0=v0, r1=v1,...,r10=v10,r11='',...r93='') 
		. . .
 	{Record}(r0=v0, r1=v1,...,r10=v10,r11='',...r93='')]

In the first section of code, I process some of the first 10 columns
(r0=v0, r1=v1,...,r10=v10), and place the results in blank columns, also
in the first 10 columns.

In the second section of code, I'd like to put calculated values in
columns 11-93 (r11='',...r63=''), in which 3 columns will be calculated
28 times for each Record.

Is there a way to do this as a step in the loop:

for idx, r in enumerate(records):

    . . . 

    (ideally I'd like to have a loop here, or a function, that would 
	calculate the 28 triplets 
     	and replace their empty namedtuples with their calculated
values, 
	but this is what I've failed to successfully do.)

I've tried writing a function, to either calculate and write 1) all 28
triplets, 2) one triplet, or 3) one column at a time, that would be
called in the body of the main loop. 

The general form of this function has been:

def savedata(Records, row, column, data):
     r = Records[row]
     col = getattr(r, column)
     r = r._replace(col = data)

but in every case I've tried this, it has failed.

Because, I can't say

    r = r._replace(getattr(r, column) = data)

because that gets "can't assign to a function call".

And while col ( = getattr(r, column) ) holds the correct value before

    r = r._replace(col = data)

all I get for r.column after the ._replace is an empty string, and I
have no idea how that happens.

I'm about to rewrite to process first 10 columns as namedtuples, and
then unroll the namedtuples into a list of lists, and process the 28
triplets in two for loops. 

That will work, but I'm wondering if anyone can suggest a way to make my
function, or one that accomplishes the same task, so as to preserve the
namedtuples, and avoid the need for a second, dual nested loop to finish
the second part of the problem.

(Note: I have the same dilemma using recordclass instead of
namedtuples.)

Deborah