rpsls游戏“(python)错误:无法连接'str'和'int'对象

def name_to_number(name):
if name == "rock":
    number = 0
elif name == "Spock":
    number = 1
elif name == "paper":
    number = 2  
elif name == "lizard":
    number = 3
else :
    number = 4
return number
def number_to_name(number):
    if number == 0:
        name = "rock"
    elif number == 1:
        name = "Spock"
    elif number == 2:
        name = "paper"
    elif number == 3:
        name = "lizard"
    else:
        name = "scissors"
    return name

import random
def rpsls(player_choice):
    print ""
    print " Player chooses " + player_choice
    player_number = name_to_number(player_choice)
    comp_number = random.randrange(0, 5)
    comp_choice = name_to_number(comp_number)
    **print " Computer chooses " + comp_choice**
    difference = (player_number - comp_choice) % 5
    if difference == 1 or difference == 2:
        print "Player wins!"
    elif difference == 3 or difference == 4:
        print "Computer wins!"
    else:
        print "Player and Computer tie!"
        print ""

rpsls("rock")
rpsls("Spock")
rpsls("paper")
rpsls("lizard")
rpsls("scissors")

================================================== =============

问题是第32行,打印“计算机选择” + comp_choice 我一直想知道这是怎么回事? 有人可以帮忙吗? (我使用**突出显示了包含错误的部分。)