Without for loop, Internal process of map is iterating actually, just without the keyword for
>>> x={'key1': [1, 2, 3], 'key2': [4, 5, 6]}
>>> map(lambda x,y:{'key1':x,'key2':y},x['key1'],x['key2'])
[{'key2': 4, 'key1': 1}, {'key2': 5, 'key1': 2}, {'key2': 6, 'key1': 3}]