pairing in a list

[jakemace]

I have an assingment which is about a chess tournament that has as many players and turns as you have given as input, and I need to update the ranking list every time according to some criteria (points earned, ELO, Alphabetical sort,etc.). If possible, every player has to change its color and has to be paired with the closest player in the ranking if they've never played before. My problem is updating the ranking algorithm. I have a list and a dict which holds the match records and players statistics but I have no idea about how to match them with the closest one in the ranking according to colors and if they have played before. So as I said I need some ideas for this part of the algortihm. I cannot share my code and I don't want any code, but just some ideas in order to figure out the algorithm. I am just a beginner and Im trying to use only the basic and fundamental things like lists and dictionaries (just standard python library) I would be so happy if you give me a hand in this.Btw the system is called the swiss system and more information can be found at wikipedia. This is my first post and if I made any mistakes please let me know. Additional info: Every player doesn't have to play with eachoter, a player cannot use the same colour 3 in a row and if thw number of players is odd, last player in the ranking gets one point without matching and the player cannot be the last one in the list again)