Is it possible replace spaces with underscores when I choose "APPEND A NUMBER TO EACH PHOTO" in Batch Change?

No, but in Yosemite (if that's the OS you have) you can batch rename files in the Finder. Multiple select them, right-click or ctrl-click and choose Rename. You'll see options to replace characters.

Matt

Is it possible replace spaces with underscores when I choose "APPEND A NUMBER TO EACH PHOTO" in Batch Change?

If you want to rename the files in the Finder as Matt Clifton described, don't do it while the files are in the iPhoto Library. Export them and reimport them after renaming them.

Or you can export the original image files (File > Export > Original) with the filename set to "Sequential". If you include he "_" into the filename string, you will get the filenames you want, without spaces.

Then reimport the exported images. The filenames will show as new version names.

Matt Clifton wrote:

No, but in Yosemite (if that's the OS you have) you can batch rename files in the Finder. Multiple select them, right-click or ctrl-click and choose Rename. You'll see options to replace characters.

Matt

NO!

If you make any changes to the contents of the iPhoto library using the finder you will destroy - you can NOT change the file names within the iphoto library at all - you can export them with new names and you can to anything you want to the exported files - you can not change then within iPhoto

LN

Is this what you're referring to via the Photos ➙ Batch Change ➙ Title to Text menu option?

which gives you this in iPhoto:

If it is then the answer to your question is yes. But remember that you're only changing the photos' title in iPhoto. To get the files outside of iPhoto with those new files names they must be exported via File ➙ Export ➙ File Export menu option with File Name = Title selected.

I think, Shirley wants to avoid the spaces before the index number, OT, and have an underscore instead to separate the number from the title. It is weird, that exporting from iPhoto will give the desired result of a string without spaces before the number, but Batch Change will insert unnecessary spaces before the index.

I agree - but in a larger sense I suspect that the OP does not understand how iphoto works and thinks at changing the title is also changing the file name which it is not - since we are getting no responses we can only guess but I think the answer is to not worry about it until the photos are needed externally and then do it while exporting - I'm guessing that changing the title within iPhoto will not solve their question - and as far as I can see there is not way to actually do it in iphoto anyway

LN

If that's the case then she'll need to follow your method: