A hopefully-simple bulk-renaming utility.
The most basic usage is simply rena <folder>, which runs against a folder, renaming everything with the pattern of item_{:10>number}, where number is the item's number when being read.
The padding amount can be adjusted with --padding <number>, and the direction with --padding-direction <direction>, and the prefix with --prefix <prefix>.
It can also run in regex mode, by default as a filter if only --match <regex> is used. If --match-rename <pattern> is also used, it renames everything based on a pattern. The exact syntax is described in --help.
See -h or --help for all flags.
Let's say there's a directory named images with the following structure:
md
image.jpg
image3.jpg
12746uju21.jpg
17f29a002.jpg
After running rena images/, it will result in:
md
item_0000000000.jpg
item_0000000001.jpg
item_0000000002.jpg
item_0000000003.jpg