run_flow() 不起作用。 MacOS 10.16.7，Safari 14.0.2。这是预期的吗？run_flow() 使用 Chrome？Python 代码改编自示例谷歌代码
credential_dir = Path.home().joinpath('.credentials')
if not credential_dir.exists(): credential_dir.mkdir()
store = Storage(credential_dir.joinpath(f'{appname}.json'))
credentials = store.get()
if not credentials or credentials.invalid:
cs = [p for p in Path.cwd().glob("**/client*.json")][0]
flow = client.flow_from_clientsecrets(cs, SCOPES)
flow.user_agent = appname
# NB this fails with Safari, set Chrome as default for this to work
credentials = tools.run_flow(flow, store, None)
return credentials