DOC: Add examples for np.strings.rfind()

Author: agriyakhetarpal

numpy/_core/strings.py

@@ -277,6 +277,18 @@ def rfind(a, sub, start=0, end=None):
     --------
     str.rfind
 
+    Examples
+    --------
+    >>> import numpy as np
+    >>> a = np.array(["Computer Science"])
+    >>> np.strings.rfind(a, "Science", start=0, end=None)
+    array([9])
+    >>> np.strings.rfind(a, "Science", start=0, end=8)
+    array([-1])
+    >>> b = np.array(["Computer Science", "Science"])
+    >>> np.strings.rfind(b, "Science", start=0, end=None)
+    array([9, 0])
+
     """
     end = end if end is not None else MAX
     return _rfind_ufunc(a, sub, start, end)