python编程从入门到实践 答案 第十章

10-1 Python 学习笔记

file_path = 'D:\IDM-download\Python编程-附件\《Python编程》' \
            '源代码文件\chapter_10\learning_python.txt'

with open(file_path) as file_object:
    print(file_object.read())

with open(file_path) as file_object:
    for line in file_object:
        print(line.rstrip())

with open(file_path) as file_object:
    lines = file_object.readlines()

for line in lines:
    print(line.rstrip())

10-2 C语言学习笔记

file_path = 'D:\IDM-download\Python编程-附件\《Python编程》' \
            '源代码文件\chapter_10\learning_python.txt'
with open(file_path) as file_object:
    lines = file_object.readlines()

for line in lines:
print(line.rstrip().replace('Python','C'))

10-3 访客

file_path = 'D:\IDM-download\Python编程-附件\《Python编程》' \
            '源代码文件\chapter_10\guest.txt'

name = input("Enter your name(Enter 'q' will quit): ")
while True:
    if name is 'q':
        break
    with open(file_path,'a') as file_object:
        file_object.write(name)
    break

10-4 访客名单

file_path = 'D:\IDM-download\Python编程-附件\《Python编程》' \
            '源代码文件\chapter_10\guest_book.txt'

while True:
    name = input("Enter your name(Enter 'q' will quit): ")
    if name is 'q':
        break
    name_book = name + ', Hello!'
    print(name_book)
    with open(file_path,'a') as file_object:
        file_object.write(name_book + '\n')
    # continue

10-5 关于编程的调查

原理同上

10-6 加法运算
这里并不是TypeError，而是ValueError，具体区别请自行百度

def count_number():
    try:
        number_1 = input("Enter the first number(Enter 'q' will quit.): ")
        if number_1 is 'q':
            exit()
        number_2 = input("Enter the second number(Enter 'q' will quit.): ")
        if number_2 is 'q':
            exit()
        sum = int(number_1) + int(number_2)
    except ValueError:
        print("Sorry")
    else:
        print(sum)

count_number()

10-7 加法计算器

def count_number():
    while True:
        try:
            number_1 = input("Enter the first number(Enter 'q' will quit.): ")
            if number_1 is 'q':
                exit()
            number_2 = input("Enter the second number(Enter 'q' will quit.): ")
            if number_2 is 'q':
                exit()
            sum = int(number_1) + int(number_2)
        except ValueError:
            print("Sorry")
        else:
            print(sum)

count_number()

10-8 猫和狗

filenames = ['cats.txt','dogs.txt','cccccc.txt']

def show_file():
    try:
        with open(filename) as file_object:
            print("The file " + filename.title() + " has the following things:")
            print(file_object.read())
    except FileNotFoundError:
        print("Sorry, the file " + filename.title() + " does not exist.")
        with open('save_files.txt','a') as a_f:
            a_f.write(filename)
for filename in filenames:
    show_file()

10-9 沉默的猫和狗

filenames = ['cats.txt','dogs.txt','cccccc.txt']

def show_file():
    try:
        with open(filename) as file_object:
            print("The file " + filename.title() + " has the following things:")
            print(file_object.read())
    except FileNotFoundError:
        # print("Sorry, the file " + filename.title() + " does not exist.")
        # with open('save_files.txt','a') as a_f:
        #     a_f.write(filename)
        pass
for filename in filenames:
    show_file()

10-10 常见单词

filename = 'alice.txt'

with open(filename) as file_object:
    contents = file_object.read()
    print(contents.count('the'))
    print(contents.lower().count('the'))

10-11 喜欢的数字

import json

filename = 'favorite_number.json'

favorite_number = input("Please enter your favorite number: ")
with open(filename,'w') as f_obj:
    json.dump(favorite_number,f_obj)

with open('favorite_number.json') as f:
    print(str(json.load(f)))

10-12 记住喜欢的数字

import json

def get_favorite_number():
    """存储了数字，显示出来"""
    filename = 'favorite_number.json'
    try:
        with open(filename) as f:
            number = json.load(f)
    except FileNotFoundError:
        return None
    else:
        return number

def get_new_number():
    """请用户输入一个数字"""
    filename = 'favorite_number.json'
    number = input("Enter number: ")
    with open(filename,'w') as f:
        json.dump(number,f)
    # return number

def show_favorite_number():
    """打印数字"""
    number = get_favorite_number()
    if number:
        print(number)
    else:
        get_new_number()
        # print(number)

show_favorite_number()

10-13 验证用户

import json

def get_stored_username():
    """如果存储了用户名，就获取它"""
    filename = 'username.json'
    try:
        with open(filename) as f_obj:
            username = json.load(f_obj)
    except FileNotFoundError:
        return None
    else:
        return username

def get_new_username():
    """提示用户输入用户名"""
    username = input("What is your name? ")
    filename = 'username.json'
    with open(filename,'w') as f_obj:
        json.dump(username,f_obj)
    return username

def greet_user():
    """问候用户，并指出其名字"""
    filename = 'username.json'
    name = input("Please tell me your name: ")
    with open(filename) as f:
        username = json.load(f)
        if name in username:
            print("Welcome back, " + name + "!")
        # username = get_stored_username()
        # if username:
            # print("Welcome back, " + username + "!")
        else:
            name = get_new_username()
            print("We'll remember you when you come back, " + name + "!")

greet_user()