[Zope] Greatly Simplifiied Script writing to session: Is there anything wrong with this?

[Redding, Matthew]

Hi All,

I was wondering if anyone could tell me why this python script (passed
no parameters)
creates session values for N_prod, N_shed, N_screen, N_pond, N_land,
N_soil that 
are all the same.

What am I doing wrong?  Is this a vaguery of the script system, and
should I use 
an external method instead?  I am running this on a Redhat 7.3 system,
updated 
to the latest patch.
_______________________________________________________________
import math
session=context.REQUEST.SESSION

#Define loss values:
N_shed_loss=10;N_screen_loss=8;N_sludge_loss=24;N_pond_loss=40;N_irrigat
ion_loss=25;N_soil_loss=25

#Calculate Components at each step, and assign to the session.
#_Manure Production
session['N_prod']=round(session['num_spu']*0.081814, 1)

#_exiting the shed
session['N_shed']=round(session['N_prod']*(1-(N_shed_loss/100)),1)

#_exiting the screens
session['N_screen']=round(session['N_shed']*(1-(N_screen_loss/100)), 1)

#_retained in sludge
session['N_sludge']=round(session['N_screen']*(N_sludge_loss/100), 1)

#_retained in the ponds
session['N_pond']=round((session['N_screen']-session['N_sludge'])*(1-(N_
pond_loss/100)), 1)

#_reaching the soil
session['N_lands']=round(session['N_pond']*(1-(N_irrigation_loss/100)),
1)

#_retained in the soil
session['N_soil']=round(session['N_lands']*(1-(N_soil_loss/100)), 1)
return

-------------------------------------------------------
THanks, 

Matt Redding

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