python-telegram-bot · Bibo-Joshi · Sep 15, 2021 · Sep 14, 2021 · Sep 14, 2021 · Sep 14, 2021
diff --git a/telegram/inline/inlinekeyboardmarkup.py b/telegram/inline/inlinekeyboardmarkup.py
@@ -48,6 +48,11 @@ class InlineKeyboardMarkup(ReplyMarkup):
     __slots__ = ('inline_keyboard',)
 
     def __init__(self, inline_keyboard: List[List[InlineKeyboardButton]], **_kwargs: Any):
+        if not self._check_keyboard_type(inline_keyboard):
+            raise ValueError(
+                "The parameter `inline_keyboard` should be a list of "
+                "list of InlineKeyboardButtons"
+            )
         # Required
         self.inline_keyboard = inline_keyboard
 

diff --git a/telegram/replykeyboardmarkup.py b/telegram/replykeyboardmarkup.py
@@ -92,6 +92,12 @@ def __init__(
         input_field_placeholder: str = None,
         **_kwargs: Any,
     ):
+        if not self._check_keyboard_type(keyboard):
+            raise ValueError(
+                "The parameter `keyboard` should be a list of list of "
+                "strings or KeyboardButtons"
+            )
+
         # Required
         self.keyboard = []
         for row in keyboard:

diff --git a/telegram/replymarkup.py b/telegram/replymarkup.py
@@ -17,7 +17,6 @@
 # You should have received a copy of the GNU Lesser Public License
 # along with this program.  If not, see [http://www.gnu.org/licenses/].
 """Base class for Telegram ReplyMarkup Objects."""
-
 from telegram import TelegramObject
 
 
@@ -31,3 +30,13 @@ class ReplyMarkup(TelegramObject):
     """
 
     __slots__ = ()
+
+    @staticmethod
+    def _check_keyboard_type(keyboard: object) -> bool:
+        """Checks if the keyboard provided is of the correct type - A list of lists."""
+        if not isinstance(keyboard, list):
+            return False
+        for row in keyboard:
+            if not isinstance(row, list):
+                return False
+        return True
diff --git a/tests/test_inlinekeyboardmarkup.py b/tests/test_inlinekeyboardmarkup.py
@@ -81,6 +81,14 @@ def test_from_column(self):
     def test_expected_values(self, inline_keyboard_markup):
         assert inline_keyboard_markup.inline_keyboard == self.inline_keyboard
 
+    def test_wrong_keyboard_inputs(self):
+        with pytest.raises(ValueError):
+            InlineKeyboardMarkup(
+                [[InlineKeyboardButton('b1', '1')], InlineKeyboardButton('b2', '2')]
+            )
+        with pytest.raises(ValueError):
+            InlineKeyboardMarkup(InlineKeyboardButton('b1', '1'))
+
     def test_expected_values_empty_switch(self, inline_keyboard_markup, bot, monkeypatch):
         def test(
             url,

diff --git a/tests/test_replykeyboardmarkup.py b/tests/test_replykeyboardmarkup.py
@@ -102,6 +102,12 @@ def test_expected_values(self, reply_keyboard_markup):
         assert reply_keyboard_markup.selective == self.selective
         assert reply_keyboard_markup.input_field_placeholder == self.input_field_placeholder
 
+    def test_wrong_keyboard_inputs(self):
+        with pytest.raises(ValueError):
+            ReplyKeyboardMarkup([[KeyboardButton('b1')], 'b2'])
+        with pytest.raises(ValueError):
+            ReplyKeyboardMarkup(KeyboardButton('b1'))
+
     def test_to_dict(self, reply_keyboard_markup):
         reply_keyboard_markup_dict = reply_keyboard_markup.to_dict()