Dynamic type casting in python

Question

I have 2 dicts:

dicts1 = {'field1':'', 'field2':1, 'field3':1.2}
dicts2 = {'field1':123, 'field2':123, 'field3':'123'}

I want to convert each value in dict2 to be the same type as the corresponding value in dict1, what's the quickest pythonic way of doing it?

Answer 1

Assuming they're compatible types:

for k, v in dicts1.iteritems():
    try:
        dicts2[k] =  type(v)(dicts2[k])
    except (TypeError, ValueError) as e:
        pass # types not compatible
    except KeyError as e:
        pass # No matching key in dict

Answer 2

This one liner will do it - but it does not check for type errors:

dicts1 = {'field1':'', 'field2':1, 'field3':1.2}
dicts2 = {'field1':123, 'field2':123, 'field3':'123'}

print {k : type(dicts1[k])(dicts2[k]) for k in dicts2}

This will also do it - and may be more readable for some:

print {k : type(dicts1[k])(v) for (k,v) in dicts2.iteritems()}