python - 根据规则获取字典的键

Question

给定一个字典

dictionary = {'Animal 1': {'Dog': 'Yes', 'Cat': 'No', 'Color': 'Black'},
              'Animal 2': {'Dog': 'Yes', 'Cat': 'No', 'Color': 'Brown'},
              'Animal 3': {'Dog': 'No', 'Cat': 'Yes', 'Color': 'Grey'}}

如何选择狗类动物？预期输出 ['Animal 1','Animal 2']

我可以使用:

pd.DataFrame.from_dict(dictionary).T.loc[pd.DataFrame.from_dict(dictionary).T["Dog"]=='Yes',:].index.to_list()

但是看起来很丑

Answer 1

您可以使用列表理解:

dictionary = {
    "Animal 1": {"Dog": "Yes", "Cat": "No", "Color": "Black"},
    "Animal 2": {"Dog": "Yes", "Cat": "No", "Color": "Brown"},
    "Animal 3": {"Dog": "No", "Cat": "Yes", "Color": "Grey"},
}

out = [k for k, d in dictionary.items() if d.get("Dog") == "Yes"]
print(out)

打印:

['Animal 1', 'Animal 2']