merging Python dictionaries

Question

I am trying to merge the following python dictionaries as follow:

dict1= {\'paul\':100, \'john\':80, \'ted\':34, \'herve\':10}
dict2 = {\'paul\':\'a\', \'joh         


        

Answer 1

In Python2.7 or Python3.1 you can easily generalise to work with any number of dictionaries using a combination of list, set and dict comprehensions!

>>> dict1 = {'paul':100, 'john':80, 'ted':34, 'herve':10}
>>> dict2 = {'paul':'a', 'john':'b', 'ted':'c', 'peter':'d'}
>>> dicts = dict1,dict2
>>> {k:[d.get(k) for d in dicts] for k in {k for d in dicts for k in d}}
{'john': [80, 'b'], 'paul': [100, 'a'], 'peter': [None, 'd'], 'ted': [34, 'c'], 'herve': [10, None]}

Python2.6 doesn't have set comprehensions or dict comprehensions

>>> dict1 = {'paul':100, 'john':80, 'ted':34, 'herve':10}
>>> dict2 = {'paul':'a', 'john':'b', 'ted':'c', 'peter':'d'}
>>> dicts = dict1,dict2
>>> dict((k,[d.get(k) for d in dicts]) for k in set(k for d in dicts for k in d))
{'john': [80, 'b'], 'paul': [100, 'a'], 'peter': [None, 'd'], 'ted': [34, 'c'], 'herve': [10, None]}