python头歌练习五

1.Abstraction of objects and classes

1.1the_student_class

class Student:
    def __init__(self, name, number):
        self.name = name
        self.scores = [0] * number

    def getName(self):
        return self.name

    def getScore(self, i):
        if 1 <= i <= len(self.scores):
            return self.scores[i - 1]
        else:
            raise IndexError("Index out of range")

    def setScore(self, i, score):
        if 1 <= i <= len(self.scores):
            self.scores[i - 1] = score
        else:
            raise IndexError("Index out of range")

    def getAverage(self):
        return sum(self.scores) / len(self.scores)

    def getHighScore(self):
        return max(self.scores)

    def __str__(self):
        score_str = " ".join(str(score) for score in self.scores)
        return f"Name: {self.name}\nScores: {score_str}"

1.2library_borrow_system

class Book:
    def __init__(self, title, author, year):
        self.title = title
        self.author = author
        self.year = year
        self.status = "Available"  # 将初始状态改为 "Available"，与测试用例输出更匹配

    def check_out(self):
        if self.status == "Checked out ":
            print(f'"{self.title}" is already checked out.')
        else:
            self.status = "Checked out "
            print(f'"{self.title}" has been checked out.')

    def return_book(self):
        if self.status == "Available":
            print(f'"{self.title}" was not checked out.')
        else:
            self.status = "Available"
            print(f'"{self.title}" has been returned.')


class Library:
    def __init__(self):
        self.books = []

    def add_book(self, book):
        self.books.append(book)

    def list_books(self):
        for book in self.books:
            print(f'"{book.title}" by {book.author} ({book.year}) - {book.status}')

2.function

2.1anagram_checker

def prompt_get_strings():
    print('Enter two strings and I\'ll tell you if they are anagrams: ')

def get_first_string():
    while True:
        first_string = input('Enter the first string: ')
        cleaned_first_string = ''.join(char.lower() for char in first_string if char.isalpha())
        if cleaned_first_string and len(cleaned_first_string) > 1:
            return cleaned_first_string
        else:
            print('A valid input is required')

def get_second_string():
    while True:
        second_string = input('Enter the second string: ')
        cleaned_second_string = ''.join(char.lower() for char in second_string if char.isalpha())
        if cleaned_second_string and len(cleaned_second_string) > 1:
            return cleaned_second_string
        else:
            print('A valid input is required')

def is_anagram(first_string, second_string):
    sorted_first = sorted(first_string)
    sorted_second = sorted(second_string)
    return sorted_first == sorted_second

def print_is_anagram(first_string, second_string):
    if is_anagram(first_string, second_string):
        print(f'{first_string} and {second_string} are anagrams.')
    else:
        print(f'{first_string} and {second_string} are not anagrams.')

if __name__ == "__main__":
    prompt_get_strings()
    first_string = get_first_string()
    second_string = get_second_string()
    print_is_anagram(first_string, second_string)

2.2pay_off_credit_card

import math

# 获取有效的信用卡偿还余额函数
def get_balance():
    while True:
        try:
            balance = int(input('What is your loan balance? '))
            return balance
        except ValueError:
            print('A valid input is required')

# 获取有效的年利率 APR 函数，APR 必须为整数
def get_apr():
    while True:
        try:
            apr = int(input('What is the APR on the loan (as a percent)? '))
            return apr
        except ValueError:
            print('A valid input is required')

# 获取有效的月偿还额整数函数
def get_monthly_payments():
    while True:
        try:
            monthly_payment = int(input('What are the monthly payment you can make? '))
            return monthly_payment
        except ValueError:
            print('A valid input is required')

# 计算还清需要月份数函数
def calculate_months_until_paid_off(balance, apr, monthly_payment):
    daily_rate = apr / 100 / 365
    monthly_rate = (1 + daily_rate)**30 - 1
    n = -1 * math.log(1 - balance * monthly_rate / monthly_payment) / math.log(1 + monthly_rate)
    return math.ceil(n)

# 打印还清需要月份信息函数
def print_months_take_to_pay(months):
    print(f'It will take you {months} months to pay off this loan')

if __name__ == "__main__":
    balance = get_balance()
    apr = get_apr()
    monthly_payment = get_monthly_payments()
    months_until_paid_off = calculate_months_until_paid_off(balance, apr, monthly_payment)
    print_months_take_to_pay(months_until_paid_off)

2.3password_strength_indicator

# 导入正则库
import re

# 定义获取有效密码的函数，输入密码长度不小于1
def get_password():
    while True:
        password = input('Enter password: ')
        if len(password) >= 1:  # 补充代码判定输入密码长度不小于1
            return password
        else:
            print('The password length must be at least 1.')

# 定义判断密码强度等级并打印输出判断结果的函数
def password_validator(password):
    # 定义包含不同字符类别的标识  
    has_lower = re.search(r'[a-z]', password) is not None  # 含小写字母
    has_upper = re.search(r'[A-Z]', password) is not None  # 含大写字母
    has_digit = re.search(r'[0-9]', password) is not None  # 含数字
    has_special = re.search(r'[!@#$%^&*(),.?":{}|<>]', password) is not None  # 这些是特殊字符
    if len(password) <8 and password.isdigit():# 补充代码实现8位以下全数字是非常弱密码的判断条件
        print(f'The password \'{password}\' is a very weak password')
    elif len(password) < 8 and not password.isdigit(): # 补充代码实现8位以下有数字外字符是弱密码的判断条件
        print(f'The password \'{password}\' is a weak password')
    elif len(password) >= 8 and has_digit and (has_lower or has_upper) and not has_special:
        # 补充代码实现不少于8位含字母、数字，不含特殊字符是强密码的判断条件
        print(f'The password \'{password}\' is a strong password')
    elif len(password) >= 8 and has_digit and (has_lower or has_upper) and has_special:
        # 补充代码实现不少于8位含字母、数字、特殊字符是非常强密码的判断条件
        print(f'The password \'{password}\' is a very strong password')
    else:
        print("Unable to determine the strength level")


if __name__ == "__main__":    
    
    password = get_password()
    password_validator(password)