Adder: app.py
Main source code for the Adder application.
The most basic Grok app that is still of some use: an adding machine with tape.
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The file app.py in the adder package contains all of the Python code for the Adder application.
import grok
from persistent.list import PersistentList
class Adder(grok.Application, grok.Model):
"""An adding machine with tape
>>> adder = Adder()
>>> adder.total
0.0
>>> adder.addTerm(0)
0.0
>>> '%.2f' % adder.addTerm(1.2)
'1.20'
>>> '%.2f' % adder.addTerm(-1)
'0.20'
Besides adding, Adder also contains a history of the added terms
>>> ['%.2f' % term for term in adder.terms]
['0.00', '1.20', '-1.00']
"""
def __init__(self):
super(Adder, self).__init__()
self.message = None
self.clear()
def clear(self):
self.terms = PersistentList()
self.total = 0.0
def addTerm(self, term):
self.terms.append(term)
self.total += term
return self.total
class Index(grok.View):
message = None
def update(self, term=None):
if self.request.has_key('bt_clear'):
self.context.clear()
elif term:
try:
term = float(term)
except ValueError:
self.message = "Invalid number."
else:
self.context.addTerm(term)
