python 从入门到实践 第五章习题 （高级编程技巧 week3-1）

python 从入门到实践 第五章习题 （高级编程技巧 week3-1）

5.1

这里主要就讲了一些条件语句的判断条件。
其中我们以前可能没有接触过的就是这样的语句：检测某特定值是否在列表中。
这里有个新的关键词：in

5-2

print('abc' == 'abc')

if "aBc".lower() == "abc":
    print("True")

if 4 != 4:
    print("Not equal")
else:
    print("Equal")


l = range(1,11)
print(1 in l)
print(11 in l)

print(1 in l and 2 in l) # return True
print(1 in l or 11 in l) # return True

5.3 if语句

基本的格式：

if conditional_test:
    dodododo
else:
    dodododo

当然还有另外一种结构：

if comditional_test:
    dodododo
elif comditional_test2:
    dodododo
elif conditional_test3:
    dodododo
else:
    dodododo

5-4

alien_color = "green"
if alien_color == "green":
    print("You shoot a green alien! You got five points")
else:
    print("You got ten points!")

5-6 人生的不同阶段

age = 20
if age < 2:
    print("He is a baby.")
elif 2 <= age and age < 4:
    print("He is learning walking.")
elif 4 <= age and age < 13:
    print("He is a child.")
elif 13 <= age and age < 20:
    print("He is a teenager.")
elif 20 <= age and age < 65:
    print("He is an adult.")
else:
    print("He is an old man.")

5-7 喜欢的水果

favorite_fruits = ["apple", "orange", "banana"]
if "apple" in favorite_fruits:
    print("You really like apples." )
elif "orange" in favorite_fruits:
    print("You really like oranges." )
elif "banana" in favorite_fruits:
    print("You really like bananas." )
elif "pear" in favorite_fruits:
    print("You really like pears.")
elif "blueberry" in favorite_fruits:
    print("You really like bluebarries.")

5.4 使用if语句处理列表

5-8 / 5-9

users = ["admin", "John", "Mike", "Amy", "Lily"]
if users:
    for name in users:
        if name == "admin":
            print("Hello admin, would you like to see a status report?")
        else :
            print("Hello ", name, ", thank you for logging in again")
else:
    print("We need to find some users!")

5-10

current_users = ["John", "Mike", "Amy", "Lily","Yaron"]
new_users = ["John", "Walker", "Mike", "Kuly", "Amy"]
for user in new_users:
    if user.title() in current_users:
        print("please use another username")
    else:
        print("This user name haven't been used!")