如果键重复，如何在字典中将2个值加在一起？

Question

因此，我在这个项目中要求用户输入.txt文件的数量，这些文件的标题为“ day”，然后按升序排列。 代码内部的格式是运动/活动（键），然后是逗号和进行运动（值）的人数。 我想要的是从文本文件中提供所有运动的输出，如果活动（键）被复制，那么它将加总执行该操作的人（值）。 最重要的是，我希望参加的人员总数（所有值加在一起）

days = int(input("How many days of records do you have? "))
i = 0
list1 = []
d = {}
for i in range(days):
  i += 1
  file = 'day' + str(i)
  f = open(file + '.txt')
  a = []
  for line in f:
    line = line.replace(',' , ' ')
    list1.append(line)
    words = line.split()
    d[words[0]] = words[1]
    a.append[words[1]] 
  stripped_line = [s.rstrip() for s in d]
for key,value in d.items() :
   print (key + "," + value)
print("In total:", a, "attendees.") 

INPUT

User_input = 3

day1.txt

swimming,1000
fencing,200
athletics,600
gymnastics,1200
tennis,500

day2.txt

diving,600
swimming,1200
tennis,500
rugby,900
handball,500
hockey,2300
trampoline,200

day3.txt

swimming,400
gymnastics,1200
fencing,100
diving,400
tennis,600
rugby,600

预期的输出

swimming: 2600
fencing: 300
athletics: 600
gymnastics: 2400
tennis: 1600
diving: 1000
rugby: 1500
handball: 500
hockey: 2300
trampoline: 200
In total: 13000 attendees.

电流输出

swimming,400
fencing,100
athletics,600
gymnastics,1200
tennis,600
diving,400
rugby,600
handball,500
hockey,2300
trampoline,200

Answer 1

这是使用collections.defaultdict一种方法。

例如：

from collections import defaultdict

days = int(input("How many days of records do you have? "))

result = defaultdict(int)
for i in range(days):
    with open("day{}.txt".format(i)) as infile:
        for line in infile:
            key, value = line.strip().split(",")
            result[key] += int(value)

for key,value in result.items():
    print (key + "," + str(value))

print("In total: {} attendees.".format(sum(result.values())))