在使用BigQuery Python客户端时，如遇到写入结果出现permission denied错误，可能是因为Google Cloud Storage存储桶权限设置不正确，需要为该存储桶授权给BigQuery服务账号。可以参考以下代码示例，将存储桶的访问权限设置为authorized_viewers，确保BigQuery服务账号被授权访问。

from google.cloud import storage

# set storage client
storage_client = storage.Client()

# set bucket
bucket = storage_client.bucket('your-bucket-name')

# set bucket IAM policy
policy = bucket.get_iam_policy(requested_policy_version=3)

# add bigquery service account as an authorized viewer
policy.bindings.append({
                            "role": "roles/storage.objectViewer",
                            "members": {"serviceAccount": "bigquery-{project-id}@bigquery-encryption.iam.gserviceaccount.com"}
})

# set bucket IAM policy
bucket.set_iam_policy(policy)

需要注意的是，your-bucket-name应该替换为您自己的存储桶名称，bigquery-{project-id}@bigquery-encryption.iam.gserviceaccount.com应该替换为您自己的BigQuery服务账号ID。