testing encoding in kwargs to to_clipboard and test case for the same

Author: Ajay Saxena

pandas/io/clipboard.py

@@ -74,6 +74,12 @@ def to_clipboard(obj, excel=None, sep=None, **kwargs):  # pragma: no cover
       - Windows:
       - OS X:
     """
+    encoding  = kwargs.get('encoding')
+
+    #testing if an invalid encoding is passed to clipboard
+    if encoding is not None and encoding is not 'utf-8':
+        raise ValueError('clipboard only supports utf-8 encoding')
+
     from pandas.util.clipboard import clipboard_set
     if excel is None:
         excel = True

pandas/io/tests/test_clipboard.py

@@ -117,3 +117,11 @@ def test_read_clipboard_infer_excel(self):
 
         tm.assert_frame_equal(res, exp)
 
+    #test case for testing invalid encoding
+    def test_invalid_encoding(self):
+        data = self.data['string']
+        with tm.assertRaises(ValueError):
+            data.to_clipboard(encoding='ascii')
+
+    
+