client = DropboxClient(ACCESS_TOKEN)
path = 'test.data'
chunk_size = 1024 * 1024
total_size = os.path.getsize(path)
upload_id = None
offset = 0
with open(path, 'rb') as f:
    while offset < total_size:
        offset, upload_id = client.upload_chunk(BytesIO(f.read(chunk_size)),
            offset=offset, upload_id=upload_id)
print('Uploaded so far: {} bytes'.format(offset))
client.commit_chunked_upload('auto/test.data', upload_id)
print('Upload complete.')
Progress bar while uploading a file to dropbox