Remove duplicate dict in list in Python

Question

I have a list of dicts, and I\'d like to remove the dicts with identical key and value pairs.

For this list: [{\'a\': 123}, {\'b\': 123}, {\'a\': 123}]<

Answer 1

Not a universal answer, but if your list happens to be sorted by some key, like this:

l=[{'a': {'b': 31}, 't': 1},
   {'a': {'b': 31}, 't': 1},
 {'a': {'b': 145}, 't': 2},
 {'a': {'b': 25231}, 't': 2},
 {'a': {'b': 25231}, 't': 2}, 
 {'a': {'b': 25231}, 't': 2}, 
 {'a': {'b': 112}, 't': 3}]

then the solution is as simple as:

import itertools
result = [a[0] for a in itertools.groupby(l)]

Result:

[{'a': {'b': 31}, 't': 1},
{'a': {'b': 145}, 't': 2},
{'a': {'b': 25231}, 't': 2},
{'a': {'b': 112}, 't': 3}]

Works with nested dictionaries and (obviously) preserves order.