two_thirds_random

Use rpsrunner.py to play unranked matches on your computer.

Source code:

import random

if input == "": # initialize variables for the first round
    rockCount = paperCount = scissorsCount = 0
elif input == "R":
    rockCount += 1
elif input == "P":
    paperCount += 1
elif input == "S":
    scissorsCount += 1

if rockCount > paperCount and rockCount > scissorsCount:
    output = random.choice(["P", "R"])  # paper beats rock
elif paperCount > scissorsCount:
    output = random.choice(["S", "P"])  # scissors beats paper
else:
    output = random.choice(["R", "S"])  # rock beats scissors