Question

我在python 2.7中制作了一个程序，它将滚动骰子，然后计算每个数字被滚动的次数。但似乎无法弄清楚这个问题。

它返回：Traceback（最近一次调用最后一次）：文件＆＃34; DiceRoller.py＆＃34;，第16行，in counter [s] + = 1 KeyError：3 来自随机导入randint

while True:
    z = raw_input("How many sides should the dice(s) have?\n> ")
    i = 0
    x = raw_input("How many dices do you want?\n> ")
    dice = {}
    while i <= int(x):

        dice[i] = randint(1,int(z))
        i += 1

    counter = {}
    for p, s in dice.iteritems():
        counter[s] += 1

    print counter

    raw_input("Return to restart.")

Answer 1

您将每个计数器设置为值+1：

counter[s] =+ 1
#           ^^^

您没有在那里使用+=; Python将其视为：

counter[s] = (+1)

交换+和=：

counter[s] += 1

这会引发异常，因为第一次键s不会出现;在这种情况下使用counter.get()获取默认值：

counter[s] = counter.get(s, 0) + 1

或使用collections.defaultdict() object而不是常规词典：

from collections import defaultdict

counter = defaultdict(int)
for s in dice.itervalues():
    counter[s] =+ 1

或使用collections.Counter() object进行计数：

from collections import Counter

counter = Counter(dice.itervalues())

Answer 2

使用xrange并随时增加每个计数，如果你只想计算每一方滚动的次数，则不需要使用两个dicts：

from collections import defaultdict
from random import randint
z = int(raw_input("How many sides should the dice(s) have?\n> "))
x = int(raw_input("How many dices do you want?\n> "))

counts = defaultdict(int) # store dices sides as keys, counts as values

# loop in range of how many dice
for _ in xrange(x):
    counts[randint(1,z)] += 1 


for side,count in counts.iteritems():
    print("{} was rolled {} time(s)".format(side,count))

输出：

How many sides should the dice(s) have?
> 6
How many dices do you want?
> 10
1 was rolled 2 time(s)
2 was rolled 3 time(s)
3 was rolled 1 time(s)
4 was rolled 1 time(s)
5 was rolled 1 time(s)
6 was rolled 2 time(s)

如果要在输出中包含所有骰子边，可以使用xrange创建计数dict：

 counts = {k:0 for k in xrange(1, z+1)}

那么输出将是：

How many sides should the dice(s) have?
> 6
How many dices do you want?
> 10
1 was rolled 0 time(s)
2 was rolled 2 time(s)
3 was rolled 0 time(s)
4 was rolled 0 time(s)
5 was rolled 5 time(s)
6 was rolled 3 time(s)

骰子计数器错误

2 个答案: