{Core} Delay import

src/azure-cli-core/azure/cli/core/commands/__init__.py

@@ -827,11 +827,13 @@ def _build_kwargs(self, func, ns):  # pylint: disable=no-self-use
 
     @staticmethod
     def remove_additional_prop_layer(obj, converted_dic):
-        from msrest.serialization import Model
-        if isinstance(obj, Model):
-            # let us make sure this is the additional properties auto-generated by SDK
-            if ('additionalProperties' in converted_dic and isinstance(obj.additional_properties, dict)):
+        # Follow EAFP to flatten `additional_properties` auto-generated by SDK
+        # See https://docs.python.org/3/glossary.html#term-eafp
+        try:
+            if 'additionalProperties' in converted_dic and isinstance(obj.additional_properties, dict):
                 converted_dic.update(converted_dic.pop('additionalProperties'))
+        except AttributeError:
+            pass
         return converted_dic
 
     def _validate_cmd_level(self, ns, cmd_validator):  # pylint: disable=no-self-use
@@ -843,12 +845,14 @@ def _validate_cmd_level(self, ns, cmd_validator):  # pylint: disable=no-self-use
             pass
 
     def _validate_arg_level(self, ns, **_):  # pylint: disable=no-self-use
-        from msrest.exceptions import ValidationError
         for validator in getattr(ns, '_argument_validators', []):
             try:
                 validator(**self._build_kwargs(validator, ns))
-            except ValidationError:
-                logger.debug('Validation error in %s.', str(validator))
+            except Exception as ex:
+                # Delay the import and mimic an exception handler
+                from msrest.exceptions import ValidationError
+                if isinstance(ex, ValidationError):
+                    logger.debug('Validation error in %s.', str(validator))
                 raise
         try:
             delattr(ns, '_argument_validators')

src/azure-cli-core/azure/cli/core/commands/arm.py

@@ -179,7 +179,6 @@ def resource_exists(cli_ctx, resource_group, name, namespace, type, **_):  # pyl
 def register_ids_argument(cli_ctx):
 
     from knack import events
-    from msrestazure.tools import parse_resource_id, is_valid_resource_id
 
     ids_metadata = {}
 
@@ -305,6 +304,7 @@ def assemble_json(ids):
         if full_id_list:
             setattr(namespace, '_ids', full_id_list)
 
+        from azure.mgmt.core.tools import parse_resource_id, is_valid_resource_id
         for val in full_id_list:
             if not is_valid_resource_id(val):
                 raise CLIError('invalid resource ID: {}'.format(val))

src/azure-cli-core/azure/cli/core/util.py

@@ -17,12 +17,8 @@
 import logging
 
 from six.moves.urllib.request import urlopen  # pylint: disable=import-error
-
-from azure.common import AzureException
-from azure.core.exceptions import AzureError
 from knack.log import get_logger
 from knack.util import CLIError, to_snake_case
-from inspect import getfullargspec as get_arg_spec
 
 logger = get_logger(__name__)
 
@@ -61,6 +57,8 @@ def handle_exception(ex):  # pylint: disable=too-many-return-statements
     from msrestazure.azure_exceptions import CloudError
     from msrest.exceptions import HttpOperationError, ValidationError, ClientRequestError
     from azure.cli.core.azlogging import CommandLoggerContext
+    from azure.common import AzureException
+    from azure.core.exceptions import AzureError
 
     with CommandLoggerContext(logger):
         if isinstance(ex, JMESPathTypeError):
@@ -477,6 +475,7 @@ def is_track2(client_class):
     """ IS this client a autorestv3/track2 one?.
     Could be refined later if necessary.
     """
+    from inspect import getfullargspec as get_arg_spec
     args = get_arg_spec(client_class.__init__).args
     return "credential" in args