随机选择python文件无法正常工作

Question

我正在尝试用Python进行闪存卡测验挑战。这涉及从文本文件中获取州和它们的首都。我设法剥离并拆分以创建带键的字典。

但每次我在for循环中使用随机选择它输出最后一个键（例如怀俄明州）另一方面，当我把它从for循环中取出时，它只输出第一个键（例如Alabama）

这是它的样子（显然这不显示文本文件）

import random
with open("state_capitals.txt","r") as f:
for line in f:
    cleanedLine = line.strip().split(',')
    state = cleanedLine[0]
    capital = cleanedLine[1]
    d = {}
    d[state] = capital
    while len(d)>0:
        choice = random.choice(list(d.keys()))

        print("What is the capital city of",choice,"?")
        answer=input("Answer:  ")

Answer 1

问题是你在while循环范围内有for循环，所以你永远不会有机会填充你的字典。但是，将while循环移到for循环之外并不能解决另一个问题;您在 d循环中初始化for ，以便不断重置为空字典，删除所有以前的条目。

import random

d = {} # Create the dict once, otherwise each loop will delete all previous entries

with open("state_capitals.txt","r") as f:
    for line in f:
        cleanedLine = line.strip().split(',')
        state = cleanedLine[0]
        capital = cleanedLine[1]
        d[state] = capital

# Move this outside the while loop. There's no need to recreate it on every iteration
states = list(d.keys())

# Move the while loop to be outside of the for loop
while len(d)>0:
    choice = random.choice(states)

    print("What is the capital city of",choice,"?")
    answer=input("Answer:  ")

    # Allow the user to type Quit/quit to break the loop
    if answer.lower() == 'quit':
        break

Answer 2

您的for位于choice = random.choice(list(d.keys()))循环内，因此在for期间，词典只有一个密钥。您还可以在每个min循环迭代中重新初始化字典。