[Python] TypeError: Object of type RelativeBy is not JSON serializable for find_elements of...

Why am I getting the error below when the method signature of find_elements apparently does support RelativeBy? I bypassed this error by not using relativeBy. Using selenium 4.33.0 and python 3.13.6


inner_elements = element.find_elements(by, value)
File "\venv\Lib\site-packages\selenium\webdriver\remote\webelement.py", line 632, in find_elements
return self._execute(Command.FIND_CHILD_ELEMENTS, {"using": by, "value": value})["value"]
~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "\venv\Lib\site-packages\selenium\webdriver\remote\webelement.py", line 574, in _execute
return self._parent.execute(command, params)
~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
File "\venv\Lib\site-packages\selenium\webdriver\remote\webdriver.py", line 445, in execute
response = self.command_executor.execute(driver_command, params)
File "\venv\Lib\site-packages\selenium\webdriver\remote\remote_connection.py", line 400, in execute
data = utils.dump_json(params)
File "\venv\Lib\site-packages\selenium\webdriver\remote\utils.py", line 23, in dump_json
return json.dumps(json_struct)
~~~~~~~~~~^^^^^^^^^^^^^
File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.13_3.13.1776.0_x64__qbz5n2kfra8p0\Lib\json\__init__.py", line 231, in dumps
return _default_encoder.encode(obj)
~~~~~~~~~~~~~~~~~~~~~~~^^^^^
File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.13_3.13.1776.0_x64__qbz5n2kfra8p0\Lib\json\encoder.py", line 200, in encode
chunks = self.iterencode(o, _one_shot=True)
File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.13_3.13.1776.0_x64__qbz5n2kfra8p0\Lib\json\encoder.py", line 261, in iterencode
return _iterencode(o, 0)
File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.13_3.13.1776.0_x64__qbz5n2kfra8p0\Lib\json\encoder.py", line 180, in default
raise TypeError(f'Object of type {o.__class__.__name__} '
f'is not JSON serializable')
TypeError: Object of type RelativeBy is not JSON serializable




I was using a relativeBy value to find an element inside a specific element. so the code was

myRelativeLocator = locate_with(By.CSS_SELECTOR, "div.someclass").below({By.CSS_SELECTOR:"h4.some_label"})
myWebsitePopupWindow.find_elements(myRelativeLocator)

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