Python字典类型

Question

我想弄清楚为什么会有这个类型的错误。能把整数放在字典里吗？

math_questions = [
    {'question1':'1*1',
    'answer1':1,
    'quote1' :'What you are,you are by accident of birth; what I am,I am by myself.\n There are and will be a thousand princes; there is only one Beethoven.'},
    {'question2':'2*1',
    'answer2':2,
    'quote2': 'Two is company, three is a crowd'},
    {'question3': '3*1',
    'answer3': 3,
    'quote3': 'There are three types of people, those who can count and those who cannot'}
    ]

# read from a txt file later???

print math_questions[0]['question1']

math_answer = int(raw_input("What is the answer to " + math_questions["question1"] +"? : "))

if math_answer == math_questions['answer1']:
    print math_questions['quote']
else:
    print "Try again"
print math_questions['answer1'] 

这是我得到的错误信息。

PS C:\python27\math_game> python math_game.py
1*1
Traceback (most recent call last):
  File "math_game.py", line 17, in <module>
    math_answer = int(raw_input("What is the answer to " + math_questions["question1"] +"? : "))
TypeError: list indices must be integers, not str
PS C:\python27\math_game>

谢谢你提前帮忙。

Answer 1

访问列表时，需要索引。看起来您正在尝试访问一个dict。相反，将：

math_answer = int(raw_input("What is the answer to " + math_questions[0]["question1"] +"? : "))

你犯了几个错误：

1. 你在第17，19，20，23行有math_questions["question1"]
2. 您有不存在的math_questions["quote"] (我改为math_questions["quote1"])

在这里，我们尝试按您使用的方式访问dict的列表。但是，在以这种方式访问它之前，我们需要将它剥离到--仅是的。

>>> obj = [{'data1': 68,
... 'data2': 34,
... 'data3': 79}]
>>> obj['data2']
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: list indices must be integers, not str
>>> obj[0]['data2']
34
>>> 

以下是您更新的代码：

math_questions = [
    {'question1':'1*1',
    'answer1':1,
    'quote1' :'What you are,you are by accident of birth; what I am,I am by myself.\n There are and will be a thousand princes; there is only one Beethoven.'},
    {'question2':'2*1',
    'answer2':2,
    'quote2': 'Two is company, three is a crowd'},
    {'question3': '3*1',
    'answer3': 3,
    'quote3': 'There are three types of people, those who can count and those who cannot'}
    ]

# read from a txt file later???

print math_questions[0]['question1']

math_answer = int(raw_input("What is the answer to " + math_questions[0]["question1"] +"? : "))

if math_answer == math_questions[0]['answer1']:
    print math_questions[0]['quote1']
else:
    print "Try again"
print math_questions[0]['answer1'] 

Answer 2

您应该重新设计您的数据结构，类似于以下内容：

class MathQuestion:
  def __init__(self, question, answer, quote):
    self.question = question
    self.answer = answer
    self.quote = quote

math_questions = [
  MathQuestion(question='1*1', answer='1', quote='What you are …'),
  MathQuestion(question='2*1', answer='2', quote='Two is company …'),
  #…
]

这允许您按以下方式处理字符串：

math_questions[0].answer