exclude coverage calculations on some exceptional lines

google/api_core/operations_v1/__init__.py

@@ -33,7 +33,7 @@
  from google.api_core.operations_v1.operations_rest_client_async import AsyncOperationsRestClient
 
  __all__ += ["AsyncOperationsRestClient", "AsyncOperationsRestTransport"]
-except ImportError:
+except ImportError: # pragma: NO COVER
  # This import requires the `async_rest` extra.
  # Don't raise an exception if `AsyncOperationsRestTransport` cannot be imported
  # as other transports are still available.

google/api_core/operations_v1/abstract_operations_base_client.py

@@ -32,7 +32,7 @@
  )
 
  HAS_ASYNC_REST_DEPENDENCIES = True
-except ImportError as e:
+except ImportError as e: # pragma: NO COVER
  HAS_ASYNC_REST_DEPENDENCIES = False
  ASYNC_REST_EXCEPTION = e
 
@@ -51,7 +51,7 @@ class AbstractOperationsBaseClientMeta(type):
 
  _transport_registry = OrderedDict() # type: Dict[str, Type[OperationsTransport]]
  _transport_registry["rest"] = OperationsRestTransport
- if HAS_ASYNC_REST_DEPENDENCIES:
+ if HAS_ASYNC_REST_DEPENDENCIES: # pragma: NO COVER
  _transport_registry["rest_asyncio"] = AsyncOperationsRestTransport
 
  def get_transport_class(

google/api_core/operations_v1/transports/__init__.py

@@ -32,7 +32,7 @@
  _transport_registry["rest_asyncio"] = cast(
  OperationsTransport, AsyncOperationsRestTransport
  )
-except ImportError:
+except ImportError: # pragma: NO COVER
  # This import requires the `async_rest` extra.
  # Don't raise an exception if `AsyncOperationsRestTransport` cannot be imported
  # as other transports are still available.

tests/asyncio/test_rest_streaming_async.py

@@ -33,7 +33,7 @@
 
 try:
  from google.auth.aio.transport import Response
-except ImportError:
+except ImportError: # pragma: NO COVER
  pytest.skip(
  "google-api-core[async_rest] is required to test asynchronous rest streaming.",
  allow_module_level=True,