dictionary 'hash'

[gyro]

Hi,
I have a collection of objects that I am currently trying to manage. 
Each object is initialized with a dictionary. The dictionaries have the 
same keys but may have different values. The initialization process is 
time consuming, so I don't want to create an object if I have already 
instantiated one using a dictionary with the 'same' items.

I would like to collect the objects in a dictionary with the objects as 
values and some identifier or hash of the initializing dictionary as the 
keys.


For instance:


idicts = [{'k1':val1,'k2':val2},
           {'k1':val3,'k2':val4},
           {'k1':val1,'k2':val2}]

for idict in idicts:
     dhash = somehashingfunction(idict)
     if not objectstoragedict.has_key(dhash):
         newobj = MyClass(idict)
         objectstoragedict[dhash] = newobj


Any ideas for 'somehashingfunction'?
The values in idict may be strings, integers, or instances of other 
classes I have created.

Presently, I am considering something like

def somehashingfunction(rdict):
     import sha
     dkeys = rdict.keys()
     dkeys.sort()
     rvals = [repr(rdict[key]) for key in dkeys]
     rstr = '_'.join(rvals)
     dhash = sha.new(rstr).hexdigest()
     return dhash


I'd appreciate any suggestions or comments.

Thanks.

-g