How to upload files in batch?

We don't currently have an official sample for that using the Python SDK in particular, but I'll pass this along as request for one.

Here's an example I put together for uploading a large files using upload sessions though: (note, I haven't tested this extensively, and it doesn't have any error handling)

f = open(file_path)
file_size = os.path.getsize(file_path)

CHUNK_SIZE = 4 * 1024 * 1024

if file_size <= CHUNK_SIZE:

    print dbx.files_upload(f.read(), dest_path)

else:

    upload_session_start_result = dbx.files_upload_session_start(f.read(CHUNK_SIZE))
    cursor = dropbox.files.UploadSessionCursor(session_id=upload_session_start_result.session_id,
                                               offset=f.tell())
    commit = dropbox.files.CommitInfo(path=dest_path)

    while f.tell() <= file_size:
        if ((file_size - f.tell()) <= CHUNK_SIZE):
            print dbx.files_upload_session_finish(f.read(CHUNK_SIZE),
                                            cursor,
                                            commit)
            break
        else:
            dbx.files_upload_session_append_v2(f.read(CHUNK_SIZE),
                                            cursor)
            cursor.offset = f.tell()

f.close()