我想根据另一个键的条件(例如Gender == 'male'
)来总结此词典列表中所有人的年龄:
list_of_dicts= [
{"Name": "Ethan", "Gender": "male", "Age": 11},
{"Name": "Nathan", "Gender": "male", "Age": 6},
{"Name": "Sophie", "Gender": "female", "Age": 14},
{"Name": "Patrick", "Gender": "male", "Age": 11}
]
以下代码完成了它,但我想知道是否有更多的Pythonic / compact方法可以做到这一点?也许类似于词典列表的SQL查询?
total_male_age = 0
for dict in list_of_dicts:
if dict.get("Gender") == "male":
total_male_age = total_male_age + dict.get("Age")
#total_male_age = 28
答案 0 :(得分:3)
这是怎么回事?
>>> sum(d['Age'] for d in list_of_dicts if d['Gender'] == 'male')
28
在技术上,您在生成器表达式上调用sum
- 可以过滤到Gender
等于“男性”的字典。
PEP 289为进一步阅读提供了一个示例。
要查找产品而不是总和:
import numpy as np
np.product([d['Age'] for d in list_of_dicts if d['Gender'] == 'male'])
如果你想在Python的标准库中找到产品:
from functools import reduce
from operator import mul
reduce(mul, (d['Age'] for d in list_of_dicts if d['Gender'] == 'male'), 1)