在字典中查找值，而不是键

Question

我需要程序从字典中选择一个随机值并询问用户密钥是什么。字典是词汇表。我希望程序先给用户一个定义。

Answer 1

解决此问题的一种方法是先从字典中获取一个随机键，然后再简单地检索该值。为此，您可以使用random 库，然后执行以下操作：

import random

glossary = {
    "water": "a transparent, odorless, tasteless liquid, a compound of hydrogen and oxygen",
    "wind": "air in natural motion",
    "fire": "a state, process, or instance of combustion in which fuel or other material is ignited and combined with oxygen"
}

correctAnswers = 0
totalQuestions = len(glossary)
while correctAnswers < totalQuestions:
    # Get a random key and value from the glossary dictionary
    word = random.choice(list(glossary.keys()))
    definition = glossary[word]

    # Present the prompt
    print("The definition is:", definition)
    answer = input("What word is this? ")

    # Determine if answer was correct
    if answer.lower() == word:
        print("Correct!")
        correctAnswers += 1
        del glossary[word]
    else:
        print("Incorrect, try again.")

这将从词汇表中输出一个随机定义，并且还将给出它所映射的键。然后它会提示用户回答他们认为这个词是什么。如果它们是正确的，则将从词汇表中删除该定义，并且将询问另一个问题是否仍然存在。

希望这能让您开始尝试做的事情。

Answer 2

这是我想出的：

import random
d = {'Key 1':'Value 1', 'Key 2':'Value 2'}
randomKey = random.choice(list(d.keys()))
print(d[randomKey])

打印一个随机值。希望这会有所帮助。

编辑： 你把代码复制错了，应该是：

random_key = random.choice(list(glossary))
print('Define: ', glossary[random_key])
input('Press return to see the definition')
print(glossary[random_key])

确保你已经导入了随机的import random

Answer 3

You can't. Python 不支持通过值从字典中检索键，因为无法保证值是不同的。但是，如果你翻转它们（定义是关键，词是价值），它会更容易做到。

从this answer到类似的问题，可以使用python的随机库，再加上一点数据操作。

要获取 python 字典的键列表，您可以使用 list(yourDict.keys() - 然后，您可以使用 random 库中的 random.choice() 来获取随机键。最后，您可以使用这个随机键作为d[] 的索引，以获得您的结果。

import random
d = {'An aquatic animal':'FISH', 'A common pet':'DOG'}
question = random.choice(list(d.keys()))
val = d[question]
print(question)
print(val)

Try it here!

请注意，对于上面的例子，如果你真的想存储单词作为key，你可以设置val = random.choice(list(d.keys)))和question = d[val]。

Answer 4

我建议这样做：

import numpy as np
dict = {"cat" : "a carnivorous mammal (Felis catus) long domesticated as a pet and for catching rats and mice.",
        "dog" : "A domesticated carnivorous mammal (Canis familiaris syn. Canis lupus subsp. familiaris) occurring as a wide variety of breeds, many of which are traditionally used for hunting, herding, drawing sleds, and other tasks, and are kept as pets.",
        "butterfly" : "Any of numerous insects of the order Lepidoptera, having four broad, usually colorful wings, and generally distinguished from the moths by having a slender body and knobbed antennae and being active during the day."}

length_dict = len(dict)
list_values = list(dict.values())
list_keys = list(dict.keys())
while True:
    r = np.random.randint(length_dict)
    print("Define: ")
    print(list_values[r])
    inp = input()
    if inp == list_keys[r]:
        print("Correct")

    else:
        print("Wrong")