Invert different types of dictionaries with mixed data types as values.
Python, 14 lines
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Copy to clipboard1 2 3 4 5 6 7 8 9 10 11 12 13 14 | def invert1(d):
dd = {}
for k, v in d.items():
if not isinstance(v, (tuple, list)): v = [v]
dd.update( [(vv, dd.setdefault(vv, []) + [k]) for vv in v] )
return dd
def invert2(d):
dd = {}
for k, v in d.items():
if not isinstance(v, (tuple, list)): v = [v]
[dd.setdefault(vv, []).append(k) for vv in v]
return dd
|
I just wanted to add a few more possibilities to the inverters in these recipes: <pre> http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/252143 http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/415100 </pre> The difference between these two can be seen using {'A': [1, 1]}: <pre> invert1({'A': [1, 1]}) --> {1: ['A']} invert2({'A': [1, 1]}) --> {1: ['A', 'A']} </pre> You can try it out with these as well: <pre> {'A': (1,), 'C': (3, 3), 'B': (2, 4)} {'A': [3, 2, 1], 'C': [3, 2], 'B': [1, 4]} {'A': 2, 'C': 4, 'B': 5, 'D': 5} {'A': 2, 'C': 4, 'B': 5, 'D': [5, 3]} {'A': [1, 2, 3], 'B': 4} </pre>
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