def test_groupby_with_wrong_input(self):
l = {'id':1, 'name':'John'}
with self.assertRaises(ValueError):
d = _groupby(l, 'id')
l = [
[{'id':1, 'name':'John'}],
[{'id':2, 'name':'Frank'},],
]
with self.assertRaises(ValueError):
d = _groupby(l, 'id')
def test_groupby(self):
l = [
{'id':1, 'name':'John'},
{'id':2, 'name':'Frank'},
{'id':3, 'name':'Tony'},
{'id':4, 'name':'Jimmy'},
{'id':3, 'name':'Sam'},
{'id':1, 'name':'Charles'},
{'id':3, 'name':'Bob'},
{'id':4, 'name':'Paul'},
{'id':1, 'name':'Michael'},
]
l_clone = _clone(l)
d = _groupby(l, 'id')
self.assertEqual(l, l_clone)
self.assertTrue(isinstance(d, dict))
self.assertEqual(len(d), 4)
self.assertTrue(all([
1 in d, 2 in d, 3 in d, 4 in d, ]))
self.assertTrue(all([
isinstance(d[1], list), isinstance(d[2], list),
isinstance(d[3], list), isinstance(d[4], list), ]))
self.assertEqual(len(d[1]), 3)
self.assertEqual(len(d[2]), 1)
self.assertEqual(len(d[3]), 3)
self.assertEqual(len(d[4]), 2)
def groupby(self, key, by_key):
"""
Group a list of dicts at key by the value of the given by_key and return a new dict.
"""
return benedict(_groupby(self[key], by_key))