字典列表 python 中的总和有例外答案

【问题标题】：sum in list of dictionaries python with exception字典列表 python 中的总和有例外
【发布时间】：2022-11-28 15:02:58
【问题描述】：

我如何从字典列表中获取金钱和支出的总和

金额=（蓝色和红色衬衫的金额）和（黄色和绿色衬衫的金额）

花费总和=（衬衫颜色蓝色和红色的花费总和）和（衬衫颜色黄色和绿色的花费总和）

我应该为衬衫颜色蓝色和红色制作新词典，为黄色和绿色制作另一个词典吗？

people = [{'name': 'A', 'shirtcolor':'blue', 'money':'100', spent:'50'}, {'name': 'B', 'shirtcolor':'red', 'money':'70', spent:'50'}, {'name': 'C', 'shirtcolor':'yellow', 'money':'100', spent:'70'}, {'name': 'D', 'shirtcolor':'blue', 'money':'200', spent:'110'},{'name': 'E', 'shirtcolor':'red', 'money':'130', spent:'50'}, {'name': 'F', 'shirtcolor':'yellow', 'money':'200', spent:'70'},{'name': 'G', 'shirtcolor':'green', 'money':'100', spent:'50'}]

预期输出：

Total Money:  500 and 400

Total spent: 260 and 190

【问题讨论】：

标签： python python-3.x list dictionary

【解决方案1】：

数据是

people = [{'name': 'A', 'shirtcolor': 'blue', 'money': '100', 'spent': '50'},
          {'name': 'B', 'shirtcolor': 'red', 'money': '70', 'spent': '50'},
          {'name': 'C', 'shirtcolor': 'yellow', 'money': '100', 'spent': '70'},
          {'name': 'D', 'shirtcolor': 'blue', 'money': '200', 'spent': '110'},
          {'name': 'E', 'shirtcolor': 'red', 'money': '130', 'spent': '50'},
          {'name': 'F', 'shirtcolor': 'yellow', 'money': '200', 'spent': '70'},
          {'name': 'G', 'shirtcolor': 'green', 'money': '100', 'spent': '50'}]

您只需要一个字典，其中颜色是键，值是一个键为“money”和“spent”的字典。然后你可以在那里添加所有条目。

color_sum = dict()
for entry in people:
    if entry['shirtcolor'] not in color_sum:
        color_sum[entry['shirtcolor']] = {'money':0, 'spent':0}
    color_sum[entry['shirtcolor']]['money'] += int(entry['money'])
    color_sum[entry['shirtcolor']]['spent'] += int(entry['spent'])

使用 defaultdict 确实使这更容易。

from collections import defaultdict

color_sum = defaultdict(lambda: {'money':0, 'spent':0})
for entry in people:
    color_sum[entry['shirtcolor']]['money'] += int(entry['money'])
    color_sum[entry['shirtcolor']]['spent'] += int(entry['spent'])

color_sum 中的结果数据将是这样的：

{'blue': {'money': 300, 'spent': 160}, 
 'red': {'money': 200, 'spent': 100}, 
 'yellow': {'money': 300, 'spent': 140}, 
 'green': {'money': 100, 'spent': 50}}

现在您可以获得所需的信息。

money_red_blue = color_sum["red"]["money"] + color_sum["blue"]["money"]
money_yellow_green = color_sum["yellow"]["money"]+ color_sum["green"]["money"]
print(f'Total money: {money_red_blue} and {money_yellow_green}')

这将输出Total money: 500 and 400

评论中的问题是如何从没有绿色和黄色之一的衬衫中获得所有的钱。在这种情况下，我们将不得不遍历字典中的聚合数据，并排除键为“green”和“yellow”的项目。

money = 0
for k, v in color_sum.items():
    if k not in {'green', 'yellow'}:
        money += v['money']
print(money)

或者作为 sum 和生成器的单行代码：

money = sum(v['money'] for k, v in color_sum.items() if k not in {'green', 'yellow'})
print(money)

【讨论】：

谢谢！我有另一个问题，因为我试图在 python 中探索更多，如果没有指定红色和蓝色怎么办（比如 Total money = (sum of not green or yellow) and (sum of green or yellow)）？你上面的代码会有什么变化？
@leafscart 我将此添加到我的答案中。

【解决方案2】：

首先，您需要检查 spent 属性。它应该有这样的语法：'spent': 40。所以人们会是这样的：

people = [{'name': 'A', 'shirtcolor':'blue', 'money':'100', 'spent':'50'}, {'name': 'B', 'shirtcolor': 'red', 'money':'70', 'spent':'50'}, {'name': 'C', 'shirtcolor':'yellow', 'money':'100', 'spent': '70'}, {'name': 'D', 'shirtcolor':'blue', 'money':'200', 'spent':'110'}, {'name': 'E', 'shirtcolor ':'red', 'money':'130', 'spent':'50'}, {'name': 'F', 'shirtcolor':'yellow', 'money':'200', 'spent ':'70'},{'name': 'G', 'shirtcolor':'green', 'money':'100', 'spent':'50'}]

然后您需要遍历列表并获取所有值。您可以通过扩展此代码来做到这一点：

money_blue = 0
for i in range(len(people)):
    if people[i]['shirtcolor'] == "blue":
        money += int(people[i]['money'])
    

print(money_blue)

【讨论】：

【解决方案3】：

您可以尝试如下：

product_list=[
    {"name": "A", "shirtcolor":"blue", "money":"100", "spent":"50"},
    {"name": "B", "shirtcolor":"red", "money":"70", "spent":"50"}, 
    {"name": "C", "shirtcolor":"yellow", "money":"100", "spent":"70"},
    {"name": "D", "shirtcolor":"blue", "money":"200", "spent":"110"},
    {"name": "E", "shirtcolor":"red", "money":"130", "spent":"50"},
    {"name": "F", "shirtcolor":"yellow", "money":"200", "spent":"70"},
    {"name": "G", "shirtcolor":"green", "money":"100", "spent":"50"}
]

print(product_list)

#sum of spent for blue and red
blueSpent = sum([int(x["spent"]) for x in product_list if x["shirtcolor"]=="blue" or x["shirtcolor"]=="red"])
print(blueSpent)

#sum of spent for green and yellow
greenSpent = sum([int(x["spent"]) for x in product_list if x["shirtcolor"]=="green" or x["shirtcolor"]=="yellow"])
print(greenSpent)

#sum of spent for blue and red
blueMoney = sum([int(x["money"]) for x in product_list if x["shirtcolor"]=="blue" or x["shirtcolor"]=="red"])
print(blueMoney)

#sum of money for green and yellow
greenMoney = sum([int(x["money"]) for x in product_list if x["shirtcolor"]=="green" or x["shirtcolor"]=="yellow"])
print(greenMoney)

【讨论】：