fix: maintain backwards compatibility for environments without grpc

Author: hebaalazzeh

packages/google-api-core/google/api_core/gapic_v1/__init__.py

@@ -30,17 +30,26 @@
 }
 
 from google.api_core.gapic_v1 import client_info
-from google.api_core.gapic_v1 import config
-from google.api_core.gapic_v1 import config_async
-from google.api_core.gapic_v1 import method
-from google.api_core.gapic_v1 import method_async
 from google.api_core.gapic_v1 import routing_header
 
 __all__ = [
     "client_info",
-    "config",
-    "config_async",
-    "method",
-    "method_async",
     "routing_header",
 ]
+
+try:
+    from google.api_core.gapic_v1 import config
+    from google.api_core.gapic_v1 import config_async
+    from google.api_core.gapic_v1 import method
+    from google.api_core.gapic_v1 import method_async
+
+    __all__.extend(
+        [
+            "config",
+            "config_async",
+            "method",
+            "method_async",
+        ]
+    )
+except ImportError:
+    pass

packages/google-api-core/tests/unit/gapic/test_lazy_imports.py

@@ -51,15 +51,25 @@
 import sys
 import google.api_core.gapic_v1
 
+try:
+    import grpc
+    has_grpc = True
+except ImportError:
+    has_grpc = False
+
 HEAVY_MODULES = [
     "google.api_core.gapic_v1.client_info",
-    "google.api_core.gapic_v1.config",
-    "google.api_core.gapic_v1.config_async",
-    "google.api_core.gapic_v1.method",
-    "google.api_core.gapic_v1.method_async",
     "google.api_core.gapic_v1.routing_header",
 ]
 
+if has_grpc:
+    HEAVY_MODULES.extend([
+        "google.api_core.gapic_v1.config",
+        "google.api_core.gapic_v1.config_async",
+        "google.api_core.gapic_v1.method",
+        "google.api_core.gapic_v1.method_async",
+    ])
+
 for mod in HEAVY_MODULES:
     if mod not in sys.modules:
         print(f"FAILED: {mod} was not eagerly loaded into sys.modules")