I have create a folder in s3, named "test" and I push "test_1.jpg", "test_2.jpg" into "test".
Now I want to use boto to delete folder "test".
What should I do?
There are no folders in S3. Instead, the keys form a flat namespace. However a key with slashes in its name shows specially in some programs, including the AWS console (see for example [Amazon S3 boto - how to create a folder?.
Instead of deleting "a directory", you can (and have to) list files by prefix and delete:
for key in bucket.list(prefix='your/directory/'): key.delete()
For more information, see S3 boto list keys sometimes returns directory key.