Revert "Update generic.py"

This reverts commit 15ecaf7.

Author: gurukiran07

pandas/core/generic.py

@@ -5075,8 +5075,9 @@ def pipe(self, func, *args, **kwargs):
         Notes
         -----
         - `agg` is an alias for `aggregate`. Use the alias.
-        - Pandas operations generally exclude NaNs. For example, `agg(np.nanmedian)`,
-          `agg(np.median)`, and `agg('median') will return the same result.
+        - Some NumPy functions resolve to their corresponding internal Cython function.
+          As pandas operations generally exclude NaNs, for example `.agg(np.nanmedian)`,
+          `.agg(np.median)`, and `.agg('median') will return the same result.
 
         A passed user-defined-function will be passed a Series for evaluation.
         {examples}"""