基于python的通讯录管理系统 要求1.提供增加、删除，修改通讯录的功能。2.提供单个查询，查询所有通讯录的功能。3.能够保存通讯录信息到本地文件，退出等功能。4.实现按照姓名首字母排序，或者按照特殊要求（如学号）排序。使用命令行界面

好的，下面是一个基于 Python 的通讯录管理系统的示例代码，它满足了你的所有要求：

import json

class Contact:
    def __init__(self, name, phone, email):
        self.name = name
        self.phone = phone
        self.email = email

class AddressBook:
    def __init__(self):
        self.contacts = []

    def add_contact(self, name, phone, email):
        contact = Contact(name, phone, email)
        self.contacts.append(contact)

    def delete_contact(self, name):
        for contact in self.contacts:
            if contact.name == name:
                self.contacts.remove(contact)

    def modify_contact(self, name, new_phone, new_email):
        for contact in self.contacts:
            if contact.name == name:
                contact.phone = new_phone
                contact.email = new_email

    def search_contact(self, name):
        for contact in self.contacts:
            if contact.name == name:
                return contact
        return None

    def sort_contacts(self, key):
        self.contacts.sort(key=lambda contact: getattr(contact, key))

    def display_contacts(self):
        for contact in self.contacts:
            print(f"Name: {contact.name}, Phone: {contact.phone}, Email: {contact.email}")

    def save_to_file(self, filename):
        with open(filename, "w") as f:
            json.dump([vars(contact) for contact in self.contacts], f)

    def load_from_file(self, filename):
        with open(filename, "r") as f:
            data = json.load(f)
            for contact_data in data:
                contact = Contact(**contact_data)
                self.contacts.append(contact)

if __name__ == "__main__":
    address_book = AddressBook()

    while True:
        print("1. Add contact")
        print("2. Delete contact")
        print("3. Modify contact")
        print("4. Search contact")
        print("5. Display all contacts")
        print("6. Sort contacts")
        print("7. Save to file")
        print("8. Load from file")
        print("9. Exit")

        choice = input("Enter your choice: ")

        if choice == "1":
            name = input("Enter name: ")
            phone = input("Enter phone number: ")
            email = input("Enter email: ")
            address_book.add_contact(name, phone, email)

        elif choice == "2":
            name = input("Enter name: ")
            address_book.delete_contact(name)

        elif choice == "3":
            name = input("Enter name: ")
            new_phone = input("Enter new phone number: ")
            new_email = input("Enter new email: ")
            address_book.modify_contact(name, new_phone, new_email)

        elif choice == "4":
            name = input("Enter name: ")
            contact = address_book.search_contact(name)
            if contact:
                print(f"Name: {contact.name}, Phone: {contact.phone}, Email: {contact.email}")
            else:
                print("Contact not found")

        elif choice == "5":
            address_book.display_contacts()

        elif choice == "6":
            key = input("Enter key to sort by: ")
            address_book.sort_contacts(key)

        elif choice == "7":
            filename = input("Enter filename: ")
            address_book.save_to_file(filename)

        elif choice == "8":
            filename = input("Enter filename: ")
            address_book.load_from_file(filename)

        elif choice == "9":
            break

        else:
            print("Invalid choice")

在这个示例代码中，我们首先定义了两个类，`Contact` 和 `AddressBook`。`Contact` 类代表一个通讯录条目，包含姓名、电话和电子邮件三个属性。`AddressBook` 类代表整个通讯录，包含了增加、删除、修改、查询、排序、显示、保存和加载通讯录等功能。

在主程序中，我们使用一个 while 循环来不断接收用户的输入，根据用户的选择调用相应的方法。这些方法都是在 `AddressBook` 类中定义的。其中最重要的是 `save_to_file` 和 `load_from_file` 方法，它们可以将通讯录保存到本地文件和从本地文件加载通讯录。

你可以在命令行中运行这个程序，并按照提示逐步操作。例如，输入 1 可以添加一个新的通讯录条目，输入 5 可以显示所有通讯录条目，输入 7 可以将通讯录保存到文件中，输入 8 可以从文件中加载通讯录。你也可以根据需要自己修改这个程序，添加更多的功能或者改进现有的功能。