On 2016-11-11 11:17, Daiyue Weng wrote: > dict1 = {'A': 'a', 'B': 'b', 'C': 'c'} > dict2 = {'A': 'aa', 'B': 'bb', 'C': 'cc'} > > I am wondering how to update dict1 using dict2 that > > only keys 'A' and 'B' of dict1 are udpated. It will result in > > dict1 = {'A': 'aa', 'B': 'bb', 'C': 'c'}
Use dict1's .update() method: >>> dict1 = {'A': 'a', 'B': 'b', 'C': 'c'} >>> dict2 = {'A': 'aa', 'B': 'bb', 'C': 'cc'} >>> desired = {'A', 'B'} >>> dict1.update({k:v for k,v in dict2.items() if k in desired}) >>> dict1 {'C': 'c', 'B': 'bb', 'A': 'aa'} or do it manually for k in dict2: if k in desired: dict1[k] = dict2[k] -tkc -- https://mail.python.org/mailman/listinfo/python-list