22. 练习:列表和成员运算符

练习:列表索引

请使用列表索引根据整型变量 month 判断特定月份有多少天,并将该值存储在整型变量 num_days 中。例如,如果 month 是 8, num_days 应该设为 31,因为第八个月份八月应该有 31 天。

请记得索引以 0 开始!

Start Quiz:

month = 8
days_in_month = [31,28,31,30,31,30,31,31,30,31,30,31]

# use list indexing to determine the number of days in month


print(num_days)

练习:列表切片

请使用列表切片记法从此列表中选择列表中的最后三个元素。提示:切片可以使用负索引!

Start Quiz:

eclipse_dates = ['June 21, 2001', 'December 4, 2002', 'November 23, 2003',
                 'March 29, 2006', 'August 1, 2008', 'July 22, 2009',
                 'July 11, 2010', 'November 13, 2012', 'March 20, 2015',
                 'March 9, 2016']
                 
                 
# TODO: Modify this line so it prints the last three elements of the list
print(eclipse_dates)

可变性练习

QUIZ QUESTION: :

假设有以下两个表达式: sentence1 sentence2

sentence1 = "I wish to register a complaint."
sentence2 = ["I", "wish", "to", "register", "a", "complaint", "."]

请将以下 Python 代码与修改后的 sentence1 sentence2 的值相匹配。如果代码会出错,请与“Error”匹配。

ANSWER CHOICES:



Python 代码

sentence1 sentence2 的值

["We", "want", "to", "register", "a", “complaint”, "."]

"I wish to register a complaint!"

Error

["I", "wish", "to", "register", "a", "complaint", "!"]

["Our Majesty", "wish", "to", "register", "a", "complaint", "."]

SOLUTION:

Python 代码

sentence1 sentence2 的值

["We", "want", "to", "register", "a", “complaint”, "."]

Error

["I", "wish", "to", "register", "a", "complaint", "!"]

["Our Majesty", "wish", "to", "register", "a", "complaint", "."]