I am attempting to make a 2D game in Pygame. Later I will convert it to kivy to deploy to mobile devices. I have searched many tutorials to get started, and I understand the basics of sprites/physics. However, I cannot find a tutorial that tells me HOW to find the location of a sprite from a sprite sheet. For example, a tutorial mentioned that I could use a drawing program to find the location of a sprite, but it didn't go into detail as to HOW you would find the location of a sprite on a large sheet of sprites.
Basically I have to find the x, y location of a sprite on a .png or .jpg spritesheet file.
For example, if I want to get the location of sonic running from a spritesheet in order to use that image my code would look like this:
sonic_running = (589, 500, 80, 80)
The first two numbers in the tuple would be the x and y location of sonic in the spritesheet, and the last two numbers in the tuple would be the height and width of that sprite. But I have no idea how to find the x and y position of the sprite in the spritesheet, or the height and width of the sprite. If anyone has worked with pygame, or game creation i'd really appreciate the help. I hope that the question was detailed enough because I am still just starting out.