[py] WebDriverWait: update documentation for until and until_not (#6711)

py/selenium/webdriver/support/wait.py

@@ -61,7 +61,13 @@ def __repr__(self):
 
     def until(self, method, message=''):
         """Calls the method provided with the driver as an argument until the \
-        return value is not False."""
+        return value does not evaluate to ``False``.
+
+        :param method: callable(WebDriver)
+        :param message: optional message for :exc:`TimeoutException`
+        :returns: the result of the last call to `method`
+        :raises: :exc:`selenium.common.exceptions.TimeoutException` if timeout occurs
+        """
         screen = None
         stacktrace = None
 
@@ -81,7 +87,14 @@ def until(self, method, message=''):
 
     def until_not(self, method, message=''):
         """Calls the method provided with the driver as an argument until the \
-        return value is False."""
+        return value evaluates to ``False``.
+
+        :param method: callable(WebDriver)
+        :param message: optional message for :exc:`TimeoutException`
+        :returns: the result of the last call to `method`, or
+                  ``True`` if `method` has raised one of the ignored exceptions
+        :raises: :exc:`selenium.common.exceptions.TimeoutException` if timeout occurs
+        """
         end_time = time.time() + self._timeout
         while True:
             try: