Seeded unit tests (#1072)

* is not -> !=

* Use pytest-randomly to seed unit tests.

deepspeed/runtime/pipe/module.py

@@ -533,7 +533,7 @@ def ckpt_layer_path(self, ckpt_dir, local_layer_idx):
         idx = local_layer_idx + self._local_start
         layer_ckpt_path = os.path.join(ckpt_dir, f'layer_{idx:02d}')
         rank_repr = self._grid._topo.get_rank_repr(rank=self.global_rank)
-        if rank_repr is not '':
+        if rank_repr != '':
             layer_ckpt_path += f'-{rank_repr}'
         layer_ckpt_path += '-model_states.pt'
         return layer_ckpt_path

deepspeed/runtime/utils.py

@@ -37,6 +37,11 @@ def ensure_directory_exists(filename):
 
 
 def set_random_seed(seed):
+    """Set the random seed for common PRNGs used during training: random, numpy, and torch.
+
+    Args:
+        seed (int): the seed to use
+    """
     import numpy
     import random
     random.seed(seed)

requirements/requirements-dev.txt

@@ -1,5 +1,6 @@
 pytest
 pytest-forked
+pytest-randomly
 pre-commit
 clang-format
 sphinx

setup.cfg

@@ -0,0 +1,3 @@
+[options.entry_points]
+pytest_randomly.random_seeder =
+    deepspeed = deepspeed.runtime.utils:set_random_seed