skip missing label and placeholder probs consistently for all input elements

nicegui/elements/color_input.py

@@ -18,8 +18,10 @@ class ColorInput(ValueElement):
         :param on_change: callback to execute when the input is confirmed by leaving the focus
         """
         super().__init__(tag='q-input', value=value, on_value_change=on_change)
-        self._props['label'] = label
-        self._props['placeholder'] = placeholder
+        if label is not None:
+            self._props['label'] = label
+        if placeholder is not None:
+            self._props['placeholder'] = placeholder
 
         with self.add_slot('append'):
             self.picker = ColorPicker(on_pick=lambda e: self.set_value(e.color))

nicegui/elements/input.py

@@ -29,9 +29,9 @@ class Input(ValueElement):
         :param on_change: callback to execute when the input is confirmed by leaving the focus
         """
         super().__init__(tag='q-input', value=value, on_value_change=on_change)
-        if label:
+        if label is not None:
             self._props['label'] = label
-        if placeholder:
+        if placeholder is not None:
             self._props['placeholder'] = placeholder
         self._props['type'] = 'password' if password else 'text'
 

nicegui/elements/number.py

@@ -22,8 +22,10 @@ class Number(ValueElement):
         self.format = format
         super().__init__(tag='q-input', value=value, on_value_change=on_change)
         self._props['type'] = 'number'
-        self._props['label'] = label
-        self._props['placeholder'] = placeholder
+        if label is not None:
+            self._props['label'] = label
+        if placeholder is not None:
+            self._props['placeholder'] = placeholder
 
     def _msg_to_value(self, msg: Dict) -> Any:
         return float(msg['args'])