실전: 주소록 관리 프로그램

import json
import os

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

    def to_dict(self):
        return {
            "name": self.name,
            "phone": self.phone,
            "email": self.email
        }

    @classmethod
    def from_dict(cls, data):
        return cls(data["name"], data["phone"], data.get("email", ""))

    def __str__(self):
        info = self.name + " | " + self.phone
        if self.email:
            info += " | " + self.email
        return info

class AddressBook:
    def __init__(self, filename="contacts.json"):
        self.filename = filename
        self.contacts = []
        self.load()

    def add(self, contact):
        self.contacts.append(contact)
        self.save()
        print(contact.name + " 추가 완료")

    def search(self, keyword):
        results = [
            c for c in self.contacts
            if keyword.lower() in c.name.lower()
            or keyword in c.phone
        ]
        return results

    def delete(self, name):
        before = len(self.contacts)
        self.contacts = [
            c for c in self.contacts if c.name != name
        ]
        if len(self.contacts) < before:
            self.save()
            print(name + " 삭제 완료")
        else:
            print(name + "을(를) 찾을 수 없습니다")

    def list_all(self):
        if not self.contacts:
            print("주소록이 비어 있습니다")
            return
        for i, c in enumerate(self.contacts, 1):
            print(str(i) + ". " + str(c))

    def save(self):
        data = [c.to_dict() for c in self.contacts]
        with open(self.filename, "w", encoding="utf-8") as f:
            json.dump(data, f, ensure_ascii=False, indent=2)

    def load(self):
        if os.path.exists(self.filename):
            with open(self.filename, "r", encoding="utf-8") as f:
                data = json.load(f)
                self.contacts = [Contact.from_dict(d) for d in data]

def main():
    book = AddressBook()
    print("=== 주소록 관리 프로그램 ===")

    while True:
        print("\n[1] 추가  [2] 검색  [3] 목록  [4] 삭제  [5] 종료")
        choice = input("선택: ").strip()

        if choice == "1":
            name = input("이름: ").strip()
            phone = input("전화번호: ").strip()
            email = input("이메일 (선택): ").strip()
            book.add(Contact(name, phone, email))

        elif choice == "2":
            keyword = input("검색어 (이름/전화): ").strip()
            results = book.search(keyword)
            if results:
                for c in results:
                    print("  ->", c)
            else:
                print("검색 결과가 없습니다")

        elif choice == "3":
            book.list_all()

        elif choice == "4":
            name = input("삭제할 이름: ").strip()
            book.delete(name)

        elif choice == "5":
            print("프로그램을 종료합니다.")
            break

        else:
            print("잘못된 입력입니다")

if __name__ == "__main__":
    main()