python的类与文件、异常的一些习题作答分享

9-1

class Restaurant():
    def __init__(self, restaurant_name, cuisine_type):
        self.restaurant_name = restaurant_name
        self.cuisine_type = cuisine_type

    def describe_restaurant(self):
        print("The name of this restaurant is: " + self.restaurant_name, end = '')
        print(', and the cuisine type is ' + self.cuisine_type)

    def open_restaurant(self):
        print("This restaurant is open!")

my_restaurant = Restaurant("Perfect Restaurant", "Chinese food")
his_restaurant = Restaurant("Italian Restaurant", "Itlian food")

my_restaurant.describe_restaurant()
my_restaurant.open_restaurant()
his_restaurant.describe_restaurant()
his_restaurant.open_restaurant()

结果如下：

9-4

class Restaurant():
    def __init__(self, restaurant_name, cuisine_type, number_served = 0):
        self.restaurant_name = restaurant_name
        self.cuisine_type = cuisine_type
        self.number_served = number_served

    def describe_restaurant(self):
        print("The name of this restaurant is: " + self.restaurant_name, end = '')
        print(', and the cuisine type is ' + self.cuisine_type)

    def open_restaurant(self):
        print("This restaurant is open!")

    def set_number_served(self, value):
        self.number_served = value
        print(self.number_served)
    
    def increment_number_served(self):
        self.number_served += 1

my_restaurant = Restaurant("Perfect Restaurant", "Chinese food")
my_restaurant.describe_restaurant()
my_restaurant.open_restaurant()
my_restaurant.set_number_served(15)
#下面将就餐人数设为35
for i in range(20):
    my_restaurant.increment_number_served()
print(my_restaurant.number_served)

结果如下：

9-6

class IceCreamStand(Restaurant):
    def __init__(self, restaurant_name, cuisine_type, number_served = 0):
        super().__init__(restaurant_name, cuisine_type, number_served)
        self.flavors = ["apple", "orange", "pineapple", "vanilla", "strawberry"]
    
    def printFlavors(self):
        print(self.flavors)

IceCreamStand0 = IceCreamStand("Ice", "Ice-cream")
IceCreamStand0.printFlavors()

输出为：

['apple', 'orange', 'pineapple', 'vanilla', 'strawberry']

9-10

from restaurant import Restaurant
my_restaurant = Restaurant("Perfect Restaurant", "Chinese food")
my_restaurant.describe_restaurant()
my_restaurant.open_restaurant()

输出为：

The name of this restaurant is: Perfect Restaurant, and the cuisine type is Chinese food
This restaurant is open!

10-1

In Python you can calculate;
In Python you can make games;
In Python you can do many things.
In Python you can calculate;
In Python you can make games;
In Python you can do many things.
In Python you can calculate;

输出结果为：

with open("learning_python.txt") as file_object:
    contents = file_object.read()
print(contents)

with open("learning_python.txt") as file_object:
    for line in file_object:
        print(line.rstrip())

with open("learning_python.txt") as file_object:
    lines = file_object.readline()
print(lines)

10-3

with open("guest.txt", 'w') as file_object:
    name = input("Please input your name:")
    file_object.write(name)

10-6

a = input("Please input a number:")
b = input("Please input a number:")
try:
    c = int(a) + int(b)
except ValueError:
    print("You shoule input number but not words!")
else:
    print(c)

结果为：