python读取文件 ，获取里面的书名和ID信息

Python通过内置的文件操作功能可以方便地读取文本文件，通常我们使用`open()`函数打开文件，然后选择适当的模式（如读取模式"r"），接着可以逐行读取内容。对于包含书名和ID的信息，假设文件是CSV、JSON或逗号分隔的格式，我们可以利用`csv`模块解析CSV，`json`模块处理JSON，或者简单地按行分割字符串。

例如，如果文件是CSV格式：

import csv

with open('books.csv', 'r') as file:
    reader = csv.reader(file)
    for row in reader:
        book_id = row[0]  # 假设第一列是ID
        book_title = row[1]  # 假设第二列是书名
        print(f'ID: {book_id}, Title: {book_title}')

如果是JSON格式：

import json

with open('books.json', 'r') as file:
    data = json.load(file)
    for item in data:
        book_id = item['id']
        book_title = item['title']
        print(f'ID: {book_id}, Title: {book_title}')

相关问题

python在jupyter中用findall和search分别实现读取txt文档中书名和ID

在Jupyter Notebook中，Python通常使用`re`模块（正则表达式库）来处理文本搜索，如查找特定模式。如果你想从.txt文档中提取书名和ID，假设它们有固定的格式，比如书名在每行开始，ID紧跟其后：

import re

# 假设文件名为'doc.txt'
with open('doc.txt', 'r') as file:
    content = file.read()

# 使用正则表达式 `^` 表示行首，`\d+` 匹配数字序列（ID），`[^0-9\s]+` 匹配非数字和空格字符（书名）
pattern = r'^\d+\s*(?P<id>\d+)\s*-\s*(?P<title>[^0-9\s]+)'

matches = re.findall(pattern, content)
book_data = [(int(match['id']), match['title']) for match in matches]

# book_data 现在是一个列表，每个元素包含一对元组 (ID, 书名)

# 输出前几项结果
for i, (id, title) in enumerate(book_data[:5]):
    print(f"第{i + 1}条记录: ID {id}, 书名 {title}")

这里我们首先打开文件并读取内容，然后定义了一个正则表达式模式。`search`函数可以在整个字符串中返回第一个匹配的结果，而`findall`则会找到所有匹配的部分，并返回一个匹配列表。

用python20.创建一个名为Student的类，包含姓名、学号和年级属性。从文件中读取数据并创建Student对象列表。将这些对象按学号排序并将结果写入另一个文件。 21.创建一个名为Book的类，包含书名、作者和价格属性。从文件中读取数据并创建Book对象列表。找出价格最高的书并输出书名和作者。 22.创建一个名为Employee的类，包含名字、工号和薪水属性。从文件中读取数据并创建Employee对象列表。将这些对象按薪水排序并将结果写入另一个文件。 23.创建一个名为Person的类，包含姓名、年龄和性别属性。从文件中读取数据并创建Person对象列表。将这些对象按年龄从大到小排序并将结果写入另一个文件。 创建一个名为Rectangle的类，包含长和宽属性。从文件中读取数据并创建Rectangle对象列表。计算并输出所有矩形对象的周长和面积之和。

好的，我已经了解您的要求了，下面是代码：

20.

class Student:
    def __init__(self, name, student_id, grade):
        self.name = name
        self.student_id = student_id
        self.grade = grade

def read_students(file_name):
    student_list = []
    with open(file_name, 'r') as f:
        lines = f.readlines()
        for line in lines:
            data = line.strip().split(',')
            student_list.append(Student(data[0], data[1], data[2]))
    return student_list

def write_students(student_list, file_name):
    student_list.sort(key=lambda x: x.student_id)
    with open(file_name, 'w') as f:
        for student in student_list:
            f.write(f'{student.name},{student.student_id},{student.grade}\n')

students = read_students('students.txt')
write_students(students, 'sorted_students.txt')

21.

class Book:
    def __init__(self, title, author, price):
        self.title = title
        self.author = author
        self.price = price

def read_books(file_name):
    book_list = []
    with open(file_name, 'r') as f:
        lines = f.readlines()
        for line in lines:
            data = line.strip().split(',')
            book_list.append(Book(data[0], data[1], float(data[2])))
    return book_list

def find_highest_priced_book(book_list):
    highest_priced_book = book_list[0]
    for book in book_list:
        if book.price > highest_priced_book.price:
            highest_priced_book = book
    return highest_priced_book

books = read_books('books.txt')
highest_priced_book = find_highest_priced_book(books)
print(f'The highest priced book is {highest_priced_book.title} by {highest_priced_book.author}.')

22.

class Employee:
    def __init__(self, name, employee_id, salary):
        self.name = name
        self.employee_id = employee_id
        self.salary = salary

def read_employees(file_name):
    employee_list = []
    with open(file_name, 'r') as f:
        lines = f.readlines()
        for line in lines:
            data = line.strip().split(',')
            employee_list.append(Employee(data[0], data[1], int(data[2])))
    return employee_list

def write_employees(employee_list, file_name):
    employee_list.sort(key=lambda x: x.salary)
    with open(file_name, 'w') as f:
        for employee in employee_list:
            f.write(f'{employee.name},{employee.employee_id},{employee.salary}\n')

employees = read_employees('employees.txt')
write_employees(employees, 'sorted_employees.txt')

23.

class Person:
    def __init__(self, name, age, gender):
        self.name = name
        self.age = age
        self.gender = gender

def read_people(file_name):
    person_list = []
    with open(file_name, 'r') as f:
        lines = f.readlines()
        for line in lines:
            data = line.strip().split(',')
            person_list.append(Person(data[0], int(data[1]), data[2]))
    return person_list

def write_people(person_list, file_name):
    person_list.sort(key=lambda x: x.age, reverse=True)
    with open(file_name, 'w') as f:
        for person in person_list:
            f.write(f'{person.name},{person.age},{person.gender}\n')

people = read_people('people.txt')
write_people(people, 'sorted_people.txt')

24.

class Rectangle:
    def __init__(self, length, width):
        self.length = length
        self.width = width

    def area(self):
        return self.length * self.width

    def perimeter(self):
        return 2 * (self.length + self.width)

def read_rectangles(file_name):
    rectangle_list = []
    with open(file_name, 'r') as f:
        lines = f.readlines()
        for line in lines:
            data = line.strip().split(',')
            rectangle_list.append(Rectangle(int(data[0]), int(data[1])))
    return rectangle_list

def calculate_total_area_and_perimeter(rectangle_list):
    total_area = 0
    total_perimeter = 0
    for rectangle in rectangle_list:
        total_area += rectangle.area()
        total_perimeter += rectangle.perimeter()
    return total_area, total_perimeter

rectangles = read_rectangles('rectangles.txt')
total_area, total_perimeter = calculate_total_area_and_perimeter(rectangles)
print(f'Total area: {total_area} sq. units')
print(f'Total perimeter: {total_perimeter} units')