Google Api获取名称显示

Question

def get_profile_info(self, credentials):
    people_service = discovery.build(serviceName='people', version='v1', credentials=credentials)
    profile = people_service.people().get(resourceName='people/me', personFields='names').execute()

    return {
        'full_name': profile['names'][0]['displayName'],
        'email': credentials.id_token['email']
    }

我不知道为什么在测试环境中可以使用相同的代码获取显示名称，但在暂存环境中却无法获取显示名称，displayName为空。请任何人知道，向我解释。预先感谢。