dict.update

Diez B. Roggisch deets at nospam.web.de
Tue Sep 2 17:16:17 CEST 2008


Mike P schrieb:
> Hi All,
> 
> I have two dictionaries e.g
> dict1 = {123:3,234:5,456:3}
> dict2 = {123:4,157:2,234:5,456:3,567:2}
> 
> I want to merge these two dictionaries together so i have a resultant
> dictionary of:
> 
> dict3 = {123:[4,3],157:[2,0],234:[5,5],456:[3,3],567:[2,0]}
> 
> As later on i want to write a csv file that would have the form
> 
> id      var1  var2
> 123     4      3
> 157     2      0
> 
> i looks like the dict.update looks almost there but i can't get it to
> work properly, can anyone offer any advise?
> 

res = {}
for d in dict1, dict2:
     for key, value in d.iteritems():
         res.setdefault(key, []).append(value)


Diez



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