[config] turn exponential notation back on for config dump (#955)

* e-notation for large floats

* handle ints too

* readability

* handle bool
Co-authored-by: NOlatunji Ruwase <olruwase@microsoft.com>

deepspeed/runtime/config.py

@@ -9,7 +9,7 @@ import copy
 
 from .constants import *
 from .fp16.loss_scaler import INITIAL_LOSS_SCALE, SCALE_WINDOW, DELAYED_SHIFT, MIN_LOSS_SCALE
-from .config_utils import get_scalar_param, dict_raise_error_on_duplicate_keys
+from .config_utils import get_scalar_param, dict_raise_error_on_duplicate_keys, ScientificNotationEncoder
 from .zero.config import DeepSpeedZeroConfig
 from .zero.constants import *
 from .activation_checkpointing.config import DeepSpeedActivationCheckpointingConfig
@@ -744,6 +744,7 @@ class DeepSpeedConfig(object):
             json.dumps(self._param_dict,
                        sort_keys=True,
                        indent=4,
+                       cls=ScientificNotationEncoder,
                        separators=(',',
                                    ':'))))
 

deepspeed/runtime/config_utils.py

@@ -6,7 +6,40 @@ Licensed under the MIT license.
 Collection of DeepSpeed configuration utilities
 """
 import json
-from collections import Counter
+from collections import Counter, Mapping, Sequence
+
+
+# adapted from https://stackoverflow.com/a/50701137/9201239
+class ScientificNotationEncoder(json.JSONEncoder):
+    """
+    This class overrides ``json.dumps`` default formatter.
+
+    This version keeps everything as normal except formats numbers bigger than 1e3 using scientific notation.
+
+    Just pass ``cls=ScientificNotationEncoder`` to ``json.dumps`` to activate it
+
+    """
+    def iterencode(self, o, _one_shot=False, level=0):
+        indent = self.indent if self.indent is not None else 4
+        prefix_close = " " * level * indent
+        level += 1
+        prefix = " " * level * indent
+        if isinstance(o, bool):
+            return "true" if o else "false"
+        elif isinstance(o, float) or isinstance(o, int):
+            if o > 1e3:
+                return f"{o:e}"
+            else:
+                return f"{o}"
+        elif isinstance(o, Mapping):
+            x = [
+                f'\n{prefix}"{k}": {self.iterencode(v, level=level)}' for k,
+                v in o.items()
+            ]
+            return "{" + ', '.join(x) + f"\n{prefix_close}" + "}"
+        elif isinstance(o, Sequence) and not isinstance(o, str):
+            return f"[{ f', '.join(map(self.iterencode, o)) }]"
+        return "\n, ".join(super().iterencode(o, _one_shot))
 
 
 class DeepSpeedConfigObject(object):
@@ -17,7 +50,12 @@ class DeepSpeedConfigObject(object):
         return self.__dict__
 
     def __repr__(self):
-        return json.dumps(self.__dict__, sort_keys=True, indent=4)
+        return json.dumps(
+            self.__dict__,
+            sort_keys=True,
+            indent=4,
+            cls=ScientificNotationEncoder,
+        )
 
 
 def get_scalar_param(param_dict, param_name, param_default_value):