take out old (1,) shape handling

Author: michaelosthege

pymc3/distributions/posterior_predictive.py

@@ -558,8 +558,6 @@ def random_sample(
             shape: Tuple[int, ...],
         ) -> np.ndarray:
             val = meth(point=point, size=size)
-            if size == 1:
-                val = np.expand_dims(val, axis=0)
             try:
                 assert val.shape == (size,) + shape, (
                     "Sampling from random of %s yields wrong shape" % param

pymc3/tests/test_shape_handling.py

@@ -211,9 +211,6 @@ def test_broadcast_dist_samples_to(self, samples_to_broadcast_to):
 def test_sample_generate_values(fixture_model, fixture_sizes):
     model, RVs = fixture_model
     size = to_tuple(fixture_sizes)
-    if size == (1,):
-        # Single draws are interpreted as scalars for backwards compatibility
-        size = tuple()
     with model:
         prior = pm.sample_prior_predictive(samples=fixture_sizes)
         for rv in RVs: