days = [["ran", "was tired"], ["ran", "was not tired"], ["didn't run", "was tired"], ["ran", "was tired"], ["didn't run", "was not tired"], ["ran", "was not tired"], ["ran", "was tired"]]
prob_tired = len([d for d in days if d[1] == "was tired"]) / len(days)
prob_ran = len([d for d in days if d[0] == "ran"]) / len(days)
prob_ran_given_tired = len([d for d in days if d[0] == "ran" and d[1] == "was tired"]) / len([d for d in days if d[1] == "was tired"])
prob_tired_given_ran = (prob_ran_given_tired * prob_tired) / prob_ran
print("Probability of being tired given that you ran: {0}".format(prob_tired_given_ran))