How to mock boto3 S3 upload in Python

import boto3
from unittest.mock import Mock, patch

class S3Uploader:
    def __init__(self, bucket_name):
        self.bucket_name = bucket_name
        self.s3 = boto3.client("s3", region_name="us-east-1")

    def upload_file(self, local_path, s3_key):
        self.s3.upload_file(local_path, self.bucket_name, s3_key)
        return {"status": "success", "bucket": self.bucket_name, "key": s3_key}

def upload_file_wrapper(uploader, local_path, s3_key):
    result = uploader.upload_file(local_path, s3_key)
    result["uploaded"] = True
    return result

if __name__ == "__main__":
    # Mock boto3 S3 client
    mock_s3 = Mock()
    mock_s3.upload_file.return_value = None

    with patch("boto3.client", return_value=mock_s3):
        uploader = S3Uploader("my-bucket")
        response = upload_file_wrapper(uploader, "file.txt", "folder/file.txt")

    print(response)
    mock_s3.upload_file.assert_called_once_with("file.txt", "my-bucket", "folder/file.txt")
    print("Mock S3 upload verified")