Should my tileset.png file have gaps between the tiles?

I’m currently using this tileset:
tileset

There are gaps between the individual tiles, which means that the tiles I’m using have larger numbers assigned to them. This makes my exported .csv file more difficult to interpret and use (I’m using pygame). Also, if I stamp one of the transparent gap tiles onto the map, it looks the same but instead of having an empty value assigned to it, it has the value of the tile I stamped (which could cause problems in pygame later on).

So, to solve these problems, should I edit my tileset to have no gaps, or is there an alternative workaround where I can manually assign numbers to the tiles in the tileset?

Thanks in advance for any help.

You could fill the empty tiles with an opaque colour such as magenta, so that you always know when they you’ve accidentally placed one.

I personally prefer to use more compact tilesets though, since all those empty tiles are a waste of memory. That would be more work to edit though, and it would break any existing maps using this tileset, since the tile IDs for each tile will change.

I am curious though, in what way do larger tile IDs make the tile data more difficult to interpret and use? With larger tilesets, even a compact style will still have large tile IDs…