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

You can use a set, but you need to turn the dicts into a hashable type.

seq = [{'a': 123, 'b': 1234}, {'a': 3222, 'b': 1234}, {'a': 123, 'b': 1234}]
unique = set()
for d in seq:
    t = tuple(d.iteritems())
    unique.add(t)

Unique now equals

set([(('a', 3222), ('b', 1234)), (('a', 123), ('b', 1234))])

To get dicts back:

[dict(x) for x in unique]