from babel.lists import format_list
format_list(['A', 'B', 'C'], style='standard-narrow', locale='de')

Traceback (most recent call last):
File "C:\Users\amelia.bruno\PycharmProjects\orion\prompt-generators\pg-sport\venv\lib\site-packages\IPython\core\interactiveshell.py", line 3437, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
File "<ipython-input-3-fdcd09f7f101>", line 1, in <module>
    format_list(['A', 'B', 'C'], style='standard-narrow', locale='de')
File "C:\Users\amelia.bruno\PycharmProjects\orion\prompt-generators\pg-sport\venv\lib\site-packages\babel\lists.py", line 82, in format_list
    result = patterns['start'].format(lst[0], lst[1])
File "C:\Users\amelia.bruno\PycharmProjects\orion\prompt-generators\pg-sport\venv\lib\site-packages\babel\localedata.py", line 218, in __getitem__
    orig = val = self._data[key]
KeyError: 'start'

format_list(['A', 'B', 'C'], style='standard-narrow', locale='en')
Out[4]: 'A, B, C'