Question at position 19 Which of the following values would NOT cause this program to exit with an error? values = ####dict = {"a": 45, "b": "Pass", "c": True, "d": -5}for key in values: print(f"{key} has value {dict[key]}")values = ["0", "1", "3" ]values = [45, "Pass", -5] values = ["a", "b", "d"] values = [0, 1, 3]Clear my selection单项选择题
A
values = ["0", "1", "3" ]
B
values = [45, "Pass", -5]
C
values = ["a", "b", "d"]
D
values = [0, 1, 3]

Question

Question at position 19 Which of the following values would NOT cause this program to exit with an error? values = ####dict = {"a": 45, "b": "Pass", "c": True, "d": -5}for key in values: print(f"{key} has value {dict[key]}")values = ["0", "1", "3" ]values = [45, "Pass", -5] values = ["a", "b", "d"] values = [0, 1, 3]Clear my selection单项选择题

A

values = ["0", "1", "3" ]

B

values = [45, "Pass", -5]

C

values = ["a", "b", "d"]

D

values = [0, 1, 3]

BlackTom AI · Accepted Answer

Dictionary lookup requires that the loop variable exactly match an existing key. Here the dictionary (named dict) maps the string keys "a", "b", "c", "d" to values 45, "Pass", True, and -5. The for loop iterates over whatever list is assigned to values and then tries to access dict[key]. If key is not one of the dictionary’s keys (or is a different type), dict[key] raises a KeyError (or TypeError if an unhashable type), causing the program to exit with an error.

Step-by-step reasoning:
1. The dictionary contents:
   - dict["a"] -> 45
   - dict["b"] -> "Pass"
   - dict["c"] -> True
   - dict["d"] -> -5
2. The loop does: for key in values: print(f"{key} has value {dict[key]}")
   - For each element of values, Python will use that element as the dictionary key lookup.
3. Evaluate each answer option:
   - values = ["0", "1", "3"]: The strings "0","1","3" are not keys in dict. First iteration tries dict["0"] → KeyError. Error occurs.
   - values = [45, "Pass", -5]: These are dictionary values, not keys. Attempting dict[45] fails because 45 is not a key (the key "a" maps to 45, but 45 is not a key). KeyError occurs on first lookup.
   - values = ["a", "b", "d"]: All three are valid keys present in dict. Lookups:
       dict["a"] → 45 (prints "a has value 45")
       dict["b"] → "Pass" (prints "b has value Pass")
       dict["d"] → -5 (prints "d has value -5")
     No error occurs.
   - values = [0, 1, 3]: Integers 0,1,3 are not keys (keys are strings), so dict[0] raises KeyError.

Why the correct answer is correct:
Only the list ["a","b","d"] supplies keys that exist in the dictionary, so each lookup succeeds and no exception is raised.

Conclusion: The value that would NOT cause the program to exit with an error is values = ["a", "b", "d"], which matches the provided answer.

类似问题

Consider this Python code: If the user inputs 10, the console output will be: Nike: [Fill in the blank] Adidas: [Fill in the blank] Reebok: [Fill in the blank]

In Python, what is a dictionary?

Question1.4 What is the result of the following Python expression? 'UNSW' in {'university': ['UNSW', 'USYD']} Select one alternative: TypeError True KeyError False ResetMaximum marks: 2

In the following Python code, what will end up in the variable y? x = { 'chuck' : 1 , 'fred' : 42, 'jan': 100} y = x.items()

You have data = {"user": {"name": "Ana", "age": 20}} . How do you access "Ana"?

Suppose we have the following Python code: s = {"apple": 1, "banana": 2} t = {"coconut": 3, "durian": 4} How would you append the key-value pairs of t to s? (the updated s should be: {"apple": 1, "banana": 2, "coconut": 3, "durian": 4})

When defining a dictionary in Python, which of the following will give you an error?

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单