Question

我有以下代码：

col_cp1_tariff_time_weekday_1_hour = 0
col_cp1_tariff_time_weekday_2_hour = 7
col_cp1_tariff_time_weekday_3_hour = 9
col_cp1_tariff_time_weekday_4_hour = 19
col_cp1_tariff_time_weekday_5_hour = 21


weekday_cents_questions = [
    "What is the tariff from the weekday time %d:00? (in cents e.g 23.5)\n" % (col_cp1_tariff_time_weekday_1_hour),
    "What is the tariff from the weekday time %d:00? (in cents e.g 23.5)\n" % (col_cp1_tariff_time_weekday_2_hour),
    "What is the tariff from the weekday time %d:00? (in cents e.g 23.5)\n" % (col_cp1_tariff_time_weekday_3_hour),
    "What is the tariff from the weekday time %d:00? (in cents e.g 23.5)\n" % (col_cp1_tariff_time_weekday_4_hour),
    "What is the tariff from the weekday time %d:00? (in cents e.g 23.5)\n" % (col_cp1_tariff_time_weekday_5_hour)]


print("You will now be asked to enter the cost per kWh for the hourly times in a 24 hour clock.")

variable_bands = [0]

for question in weekday_cents_questions:
    try:
        q = question.format(variable_bands[-1])
        cents = int(input(q))
        variable_bands.append(cents)
    except (SyntaxError, ValueError):
        variable_bands.append(0)

[col_cp1_tariff_time_weekday_1_cents,
 col_cp1_tariff_time_weekday_2_cents,
 col_cp1_tariff_time_weekday_3_cents,
 col_cp1_tariff_time_weekday_4_cents,
 col_cp1_tariff_time_weekday_5_cents] = variable_bands

print(variable_bands)

执行时，收到错误消息： ValueError：太多值无法解包（预期为5）

能否请您告诉我如何解决。我正在尝试将输入的整数分配给variable_band变量。

Answer 1

从variable_bands = [0]行开始，此列表的大小为 1。然后，您的代码向variable_bands追加了五个元素，从而使该列表的大小是6，因此是ValueError。

相反，将variable_bands = [0]更改为variable_bands = []。

但是，更改之后，您还必须从for question in weekday_cents_questions:看所有的try-except块，它仍然不起作用，因为当列表为空并且您想要要获取最后一个列表，它仍然是超出范围回溯的数组索引。相反，您必须删除question.format()部分，因为它不是必需的。

您的最终代码应该是

variable_bands = []

for question in weekday_cents_questions:
    try:
        cents = int(input(question))
        variable_bands.append(cents)
    except (SyntaxError, ValueError):
        variable_bands.append(0)

这是修改后的程序的示例运行

You will now be asked to enter the cost per kWh for the hourly times in a 24 hour clock.
What is the tariff from the weekday time 0:00? (in cents e.g 23.5)
1
What is the tariff from the weekday time 7:00? (in cents e.g 23.5)
2
What is the tariff from the weekday time 9:00? (in cents e.g 23.5)
3
What is the tariff from the weekday time 19:00? (in cents e.g 23.5)
omg
What is the tariff from the weekday time 21:00? (in cents e.g 23.5)
4
[1, 2, 3, 0, 4]

Answer 2

您应该以{{1}}开头并为空列表，否则列表中将有6个元素而不是5个元素：

variable_bands

Python ValueError：太多值无法解包（带有嵌套变量的For循环）

2 个答案: