Add a missing else condition and corresponding test case

src/sonic-py-common/sonic_py_common/device_info.py

@@ -630,7 +630,7 @@ def is_dpu():
     # Retrieve platform.json data
     platform_data = get_platform_json_data()
     if platform_data:
-        return "DPU" in platform_data
+        return 'DPU' in platform_data
 
     return False
 
@@ -956,6 +956,8 @@ def get_dpu_info():
         return platform_data["DPUS"]
     elif 'DPU' in platform_data:
         return platform_data['DPU']
+    else:
+        return {}
 
 
 def get_num_dpus():

src/sonic-py-common/tests/device_info_test.py

@@ -249,6 +249,10 @@ def test_is_dpu(self, mock_get_platform, mock_is_smartswitch, mock_get_platform_
         mock_get_platform_json_data.return_value={"DPU": {}}
         assert device_info.is_dpu() == True
 
+        # Test case where platform is a smart switch and DPU data is present in platform.json
+        mock_get_platform_json_data.return_value={"DPUS": {}}
+        assert device_info.is_dpu() == False
+
     @mock.patch("sonic_py_common.device_info.get_platform_json_data")
     @mock.patch("sonic_py_common.device_info.get_platform")
     def test_get_dpu_info(self, mock_get_platform, mock_get_platform_json_data):
@@ -273,6 +277,10 @@ def test_get_dpu_info(self, mock_get_platform, mock_get_platform_json_data):
         mock_get_platform_json_data.return_value = {"DPU": {"dpu0": {}}}
         assert device_info.get_dpu_info() == {"dpu0": {}}
 
+        # Test case where platform.json data does not contain "DPU" or "DPUS"
+        mock_get_platform_json_data.return_value = {"chassis": {}}
+        assert device_info.get_dpu_info() == {}
+
     @mock.patch("sonic_py_common.device_info.get_platform_json_data")
     @mock.patch("sonic_py_common.device_info.is_dpu")
     @mock.patch("sonic_py_common.device_info.get_platform")