如何用同一個鍵比較兩個字典列表？

Question

我必須列出字典：

basket = [{"size": "big", "food": "cheese"}, {"size": "small", "food": "cherries"}]
fruits = [{"size": "small", "food": "blueberries"}, {"size": "small", "food": "cherries"}]

我需要通過“食物”鍵比較這兩個字典列表。 如果一個水果不在籃子列表中，我想將 append 整個字典放入籃子列表中。

我試圖用 filter() 來做到這一點，但我無法想象我可以調用basket[food]並同時遍歷水果列表的場景。

Answer 1

您可以創建包含籃子中所有食物的臨時set ，然后通過不在此集合中的食物擴展basket列表：

basket = [
    {"size": "big", "food": "cheese"},
    {"size": "small", "food": "cherries"},
]
fruits = [
    {"size": "small", "food": "blueberries"},
    {"size": "small", "food": "cherries"},
]

in_basket = set(f["food"] for f in basket)

basket.extend(f for f in fruits if f["food"] not in in_basket)
print(basket)

印刷：

[
    {"size": "big", "food": "cheese"},
    {"size": "small", "food": "cherries"},
    {"size": "small", "food": "blueberries"},
]

Answer 2

你可以go通過兩個列表使用zip方法，檢查籃子列表中是否有水果列表的鍵之一，如果有你go通過水果列表並創建一個條件來檢查這個食物是否已經在列表，如果沒有，你添加

basket = [{"size": "big", "food": "cheese"}, {"size": "small", "food": "cherries"}]
fruits = [{"size": "small", "food": "blueberries"}, {"size": "small", "food": "cherries"}]

for bask, fruit in zip(basket, fruits):
  if bask['food'] == fruit['food']:
    for fruit in fruits: 
      if bask['food'] != fruit['food']:
        basket.append(fruit)

print(basket)

output：

[{'size': 'big', 'food': 'cheese'}, {'size': 'small', 'food': 'cherries'}, {'size': 'small', 'food': 'blueberries'}]