def test_arbitrarily_deep_flattening(self):
self.assertEqual(
flatten_dict({
'a': {
'v': 0,
'b': {
'c': {
'w': 1,
'd': {
'e': 2,
'x': 3
}
},
'y': 4
},
},
'z': 5,
}),
{
'a_v': 0,
'a_b_c_w': 1,
'a_b_c_d_e': 2,
'a_b_c_d_x': 3,
'a_b_y': 4,
'z': 5,
},
)
self.assertEqual(
flatten_dict(
{
'a': {
'v': 0,
'b': {
'c': {
'w': 1,
'd': {
'e': 2,
'x': 3
}
},
'y': 4
},
},
'z': 5,
},
sep=', '),
{
'a, v': 0,
'a, b, c, w': 1,
'a, b, c, d, e': 2,
'a, b, c, d, x': 3,
'a, b, y': 4,
'z': 5,
},
)
def test_specifying_separator(self):
self.assertEqual(
flatten_dict({
'a': {
'b': 'x'
},
'd': {
'e': 'y'
}
}, sep='.'),
{
'a.b': 'x',
'd.e': 'y'
},
)
self.assertEqual(flatten_dict({}, sep='.'), {})
with self.assertRaises(TypeError):
flatten_dict({}, '.')
def test_empty_nested_dictionaries_ignored(self):
self.assertEqual(
flatten_dict({
'a': {
'z': 8
},
'b': {}
}),
{'a_z': 8},
)
def test_non_dictionaries_allowed(self):
self.assertEqual(
flatten_dict({
'A': 'a',
'B': 'b',
'C': 'c'
}),
{
'A': 'a',
'B': 'b',
'C': 'c'
},
)
self.assertEqual(
flatten_dict({
'a': {
'b': 5,
'z': 20
},
'c': {
'd': 3
},
'x': 40
}),
{
'a_b': 5,
'a_z': 20,
'c_d': 3,
'x': 40
},
)
self.assertEqual(
flatten_dict({
'1': [],
'2': {},
'3': ()
}),
{
'1': [],
'3': ()
},
)
def test_flatten_with_non_strings(self):
self.assertEqual(
flatten_dict({
'a': {
1: True,
2: False
},
'b': {
3: True,
4: False
}
}),
{
'a_1': True,
'a_2': False,
'b_3': True,
'b_4': False
},
)
def test_flattening_does_not_copy(self):
original = {'a': {'b': object()}}
flattened = flatten_dict(original)
self.assertIs(flattened['a_b'], original['a']['b'])
def test_original_dict_not_changed(self):
flavors = self.flavors.copy()
flatten_dict(flavors)
self.assertEqual(flavors, self.flavors)
def test_flattening_dict_of_dicts(self):
flavors = self.flavors.copy()
self.assertEqual(flatten_dict(flavors), self.flattened_flavors)
def test_flattening_empty_dict(self):
self.assertEqual(flatten_dict({}), {})
def test_key_maker(self):
letters = {
'a': {
'v': 0,
'b': {
'c': {
'w': 1,
'd': {
'e': 2,
'x': 3
}
},
'y': 4
},
},
'z': 5,
}
flattened_letters = {
('a', 'v'): 0,
('a', 'b', 'c', 'w'): 1,
('a', 'b', 'c', 'd', 'e'): 2,
('a', 'b', 'c', 'd', 'x'): 3,
('a', 'b', 'y'): 4,
'z': 5,
}
self.assertEqual(
flatten_dict(letters, key_maker=tuple),
flattened_letters,
)
reverse_flattened_letters = {
('v', 'a'): 0,
('w', 'c', 'b', 'a'): 1,
('e', 'd', 'c', 'b', 'a'): 2,
('x', 'd', 'c', 'b', 'a'): 3,
('y', 'b', 'a'): 4,
'z': 5,
}
self.assertEqual(
flatten_dict(letters, key_maker=lambda t: t[::-1]),
reverse_flattened_letters,
)
def kingdom_joiner(keys):
return '/'.join(k.lower() for k in keys)
mammals = {
'Carnivora': {
'Canidae': {
'Canis': {'coyote', 'wolf'}
},
'Felidae': {
'Felis': {'cat'},
'Panthera': {'lion'},
}
}
}
joined_mammals = {
'carnivora/canidae/canis': {'coyote', 'wolf'},
'carnivora/felidae/felis': {'cat'},
'carnivora/felidae/panthera': {'lion'},
}
self.assertEqual(
flatten_dict(mammals, key_maker=kingdom_joiner),
joined_mammals,
)