Add get_sfp to chassis

platform/broadcom/sonic-platform-modules-accton/as5835-54x/sonic_platform/chassis.py

@@ -7,6 +7,7 @@
 #############################################################################
 
 try:
+    import sys
     import time
     from sonic_platform_pddf_base.pddf_chassis import PddfChassis
 except ImportError as e:
@@ -58,3 +59,27 @@ def get_change_event(self, timeout=2000):
             return True, change_dict
         else:
             return True, change_dict
+
+
+    def get_sfp(self, index):
+        """
+        Retrieves sfp represented by (1-based) index <index>
+
+        Args:
+            index: An integer, the index (1-based) of the sfp to retrieve.
+            The index should be the sequence of a physical port in a chassis,
+            starting from 1.
+            For example, 1 for Ethernet0, 2 for Ethernet4 and so on.
+
+        Returns:
+            An object derived from SfpBase representing the specified sfp
+        """
+        sfp = None
+
+        try:
+            # The index will start from 1
+            sfp = self._sfp_list[index-1]
+        except IndexError:
+            sys.stderr.write("SFP index {} out of range (1-{})\n".format(
+                             index, len(self._sfp_list)))
+        return sfp