onerm = float(500)
fourrm = float(450)

rpe_dict = {
    # 1 rep
    "1@10": onerm / onerm,
    "1@9,5": ((onerm / onerm)+((onerm / onerm)-(1*((onerm/onerm)-(fourrm/onerm))/3)))/2,
    "1@9": ((onerm / onerm)-(1*((onerm/onerm)-(fourrm/onerm))/3)),
    "1@8,5": (((onerm / onerm)-(1*((onerm/onerm)-(fourrm/onerm))/3))+((onerm / onerm)-(2*((onerm/onerm)-(fourrm/onerm))/3)))/2,
    "1@8": ((onerm / onerm)-(2*((onerm/onerm)-(fourrm/onerm))/3)),
    # 2 reps
    "2@10": ((onerm / onerm)-(1*((onerm/onerm)-(fourrm/onerm))/3)),
    "2@9,5": (((onerm / onerm)-(1*((onerm/onerm)-(fourrm/onerm))/3))+((onerm / onerm)-(2*((onerm/onerm)-(fourrm/onerm))/3)))/2,
    "2@9": ((onerm / onerm)-(2*((onerm/onerm)-(fourrm/onerm))/3)),
    "2@8,5": onerm / onerm,
    "2@8": fourrm / onerm,
}

for entry in rpe_dict:
    print entry, "equals ", rpe_dict[entry]

def e1rm(weight, reps, rpe):
    calc=weight/rpe_dict[str(reps)+"@"+str(rpe)]
    print calc

e1rm(100,1,8)