Are you looking for a squential batch URL downloader? WGets could be a viable solution for you. Based on a given URL pattern, WGets generates the target URLs, ,and later downloads those files automatically for you. WGets is designed to work sequentially to avoid undesired things such as being banned by the server which could be caused by firing massive requests in a short period of time.
./WGets.py "FILENAME_PRIFIX" "http://URL/'<3D>'/'<3D>'.jpg"
Since '<3D>' stands for 3 digits, WGets conceptually expands the given URL
pattern into a list of URLs which starts from http://URL/001/001.jpg to
http://URL/999/999.jpg, and later only downloads valid URLs from the list and
saves them under the downloads of the project root directory.
NOTE: Currently, '<3D>' is the only tag supported.
Though WGets does try to download all the possible derivatives of the given URL pattern, WGet doesn't generate the entire URL list, since it could be an unnecessary waste of time. In fact, we don't even have to try an URL if its preceeding URL in the same level is invalid.
To make use of the fact, WGet creates a conceptual tree. By inorderly traversing the tree and early returning in some cases, Wgets can downloads all the valid derived URLs without bumping into too many invalid ones.