Photos.app: Rename albums to zeropad numbers. Use case: Relying on sorted events and migrating from iPhoto which sorted "100" after "2" to Photos which didn't.

photos_app_zeropad.scpt

tell application "Photos"
	repeat with theAlbum in albums of folder "Events"
		set theName to name of theAlbum
		-- Zeropad initial numbers, e.g. turning "12.3 Hi" into "0012.3 Hi".
		set newName to (do shell script "ruby -e 'n = ARGV.first; num, rest = n.split(%{.}, 2); puts num.match?(/\\A\\d+\\z/) && rest ? [ num.rjust(4, %{0}), rest ].join(%{.}) : n' " & (quoted form of theName))
		set name of theAlbum to newName
	end repeat
end tell