def test_equal_to_dict(self):
d = EqualToDict({a: "a", b: "b"})
# Ensure that we call `EqualTo`.
self.assertFalse(Item.equal_to_called)
self.assertEqual(d[a], "a")
self.assertTrue(Item.equal_to_called)
self.assertEqual(d[b], "b")
self.assertTrue(a in d)
# Ensure hash collision does not occur.
self.assertEqual(hash(a.value), hash(a))
self.assertFalse(a.value in d)
# Obtaining the original representation (e.g. for `pybind11`):
# - Constructing using `dict` will not be what is desired; the keys at
# present are not directly convertible, thus would create an error.
# N.B. At present, this behavior may not be overridable via Python, as
# copying is done via `dict.update`, which has a special case for
# `dict`-inheriting types which does not have any hooks for key
# transformations.
raw_attempt = dict(d)
keys = list(raw_attempt.keys())
self.assertFalse(isinstance(keys[0], Item))
# - Calling `raw()` should provide the desired behavior.
raw = d.raw()
keys = list(raw.keys())
self.assertTrue(isinstance(keys[0], Item))
def test_constructor_map(self):
powers_in = {x: 2, y: 3, z: 4}
m = sym.Monomial(powers_in)
powers_out = EqualToDict(m.get_powers())
self.assertEqual(powers_out[x], 2)
self.assertEqual(powers_out[y], 3)
self.assertEqual(powers_out[z], 4)
def test_get_powers(self):
m = sym.Monomial(x, 2) * sym.Monomial(y) # m = x²y
powers = EqualToDict(m.get_powers())
self.assertEqual(powers[x], 2)
self.assertEqual(powers[y], 1)