用Python 3编写的小地址簿

Question

到目前为止，这个程序似乎运行得很好，但我知道它可以使用某些功能/方法更干净、效率更高。由于我还在开始编写代码，任何反馈都是非常欢迎的。

# Creating class named contacts with methods for editing and adding new 
# contacts. Also there are static methods for showing a specific or all
# contacts data and for showing if there's no contact saved on the address book.

class Contact:

    def __init__(self, name, surname, number, email):
        self.name = name
        self.surname = surname
        self.number = number
        self.email = email

    def edit_name(self, name):
        self.name = name
        return self.name

    def edit_surname(self, surname):
        self.surname = surname
        return self.surname

    def edit_number(self, number):
        self.number = number
        return self.number

    def edit_email(self, email):
        self.email = email
        return self.email

    @classmethod
    def add(cls, name, surname, number, email):
        return cls(name, surname, number, email)

    # This method prints prints all data of a specific entry it index is provided
    # otherwise it prints data of all entries saved in address book (fullnames, 
    # numbers and emails)
    @staticmethod
    def summary(index=0):
        if index == 0:
            for j in range(0, len(address_book)):
                print(address_book[j].name, address_book[j].surname, end=' / ')
                print(address_book[j].number, '/', address_book[j].email)
        else:
            print(address_book[index].name, address_book[index].surname, end=' / ')
            print(address_book[index].number, '/', address_book[index].email)
        print()
        return None

    # Prints only the names saved in the address book
    @staticmethod
    def saved():
        print('CONTACTS SAVED: ', end='')
        for j in range(0, len(address_book)):
            print(j, address_book[j].name, end=' || ')
        return None

    # Prompts the user if there's no contact saved in address book
    @staticmethod
    def isempty(list):
        if len(list) == 0:
            print('NO CONTACT SAVED\n')
            return True
        return False

该程序现在提示用户选择从0到5的范围.每个选项在地址簿中都有一个功能:添加、修改、删除、查看、查看所有、完成。

address_book = []
msg_error = '{}Invalid option{}'.format('\033[31m', '\033[m'    # Red text

access = input('Press any key to access')

while True:
    print('=-=-===-=-=-=-=-  CONTACTS MENU -=-=-=-=-=-==-==')
    print("""[ 1 ] ADD    [ 3 ] DELETE     [ 5 ] VIEW ALL
[ 2 ] MODIFY    [ 4 ] VIEW   [ 0 ] FINISH""")

  option = input('>>> ')

  #This if and elif blocks check if user input ranges from 0-5
  if not option.isnumeric():
      print(msg_error)
      continue

  elif option not in '012345':
      print(msg_error)
      continue

  # If between 0-5, convert value to integer and...
  else:
      option = int(option)

  if option == 0:
      print('>>> Program ended\n')
      break

  # Add new contact
  elif option == 1:
      name = input('Name: ').capitalize().strip()
      surname = input('Surname: ').capitalize().strip()
      number = input('Number: ').strip()
      email = input('Email: ').strip().lower()

      # Trasnform into Contact class and append to address book
      address_book.append(Contact.add(name, surname, number, email))
      print('Contact saved\n')

  # Modify a contact
  elif option == 2:
      if Contact.isempty(address_book):
          continue

      Contact.saved()
      name_index = int(input('\nModify which name? '))
      print('\nModify which entry?')
      entry_index = int(input('[ 1 ] NAME   [ 2 ] SURNAME   [ 3 ] NUMBER   [ 4 ] EMAIL\n>>>'))

      # Use object methods to modify within the list address book
      # User wants to modify name
      if entry_index == 1:
          modification = input('New name: ').capitalize().strip()
          address_book[name_index].edit_name(modification)

      # User wants to modify surname
      elif entry_index == 2:
          modification = input('New surname: ').capitalize().strip()
          address_book[name_index].edit_surname(modification)

      # User wants to modify number
      elif entry_index == 3:
          modification = input('New number: ').strip()
          address_book[name_index].edit_number(modification)

      # User wants to modify email
      elif entry_index == 4:
          modification = input('New email: ').lower().strip()
          address_book[name_index].edit_email(modification)
      print('Modification saved\n')

  # Delete a contact
  elif option == 3:
      if Contact.isempty(address_book):
          continue

      Contact.saved()
      name_index = int(input('\nWhich contact delete? '))
      del address_book[name_index]
      print('Contact deleted')

  # View specific contact details
  elif option == 4:
      if Contact.isempty(address_book):
          continue

      Contact.saved()
      index = int(input('\nContact position: '))
      Contact.summary(index)

  # View details of all contacts
  elif option == 5:
      if Contact.isempty(address_book):
          continue
      Contact.summary()

Answer 1

您正在以一种奇怪的方式使用Python类。

• 首先，如果您想创建一个新的Contact实例，只需调用Contact(name, surname, number, email)即可。不需要Contact.add，因为它做的事情完全一样。
• 接下来，您所有的静态方法。它们(几乎)与对象Contact无关，它们都操作一个联系人列表，即通讯簿。这意味着您可以使它们成为在该列表上操作的函数/内联代码，或者创建一个处理它的AddressBook类。在这种情况下，我可能会选择第一个选择。如果Contact.isempty(address_book)：继续成为如果不是address_book: print(‘没有联系人保存\n’)，继续，这使用的事实是，空列表是虚假的。Contact.saved变成print(‘contact SAVED：’'，end='')，对于j，contact in枚举(Address_book)：print(j，contact.name，end=‘)，其中迭代可迭代而不是迭代索引。您可以(也可能应该)将其放入函数中: def print_address_book(address_book)：print(“联系人保存：”，end=“”)表示j，联系人在枚举中(Address_book)：print(j，contact.name，end=‘去处“)
• 不需要所有的Contact.edit_*方法。在Python中，您通常希望避免生成getter和setter，而是使用裸属性，除非您真的必须这样做。你已经有了它们是正常的属性，所以你可以直接修改它们。但在我们这样做之前，允许字典(如访问这些条目)可能是有意义的，因此您可以使用contact["name"]而不是contact.name：class Contact：.def __getitem__(self，key)：返回getattr(self，key) def __setitem__(self，key，value)：setattr(self，key，value) --这使得更新联系人变得更加容易: name_index =int(输入(‘\nModify，哪个名称？’)而name_index不在范围(len(Address_book))：name_index =int(输入(‘\n nModify，哪个名称？'))打印(‘\n修改哪个条目？’)EMAIL\n>>>=.lower().lower()，而不输入{“名称”、“姓氏”、“数字”、“电子邮件”}：.lower(‘姓名、姓氏、号码、EMAIL\n>>> ') .lower() address_book名字_索引 = input('New：’) print('Modification \n‘)i还添加了一些代码，以确保用户输入合理的输入。
• 选择0意味着打印Contact.summary中的所有联系人(这也不应该是一种静态方法，而是一个独立的AddressBook函数或方法)不是一个好主意。这意味着您不能打印第一个联系人(请记住，Python从零开始计数)。使用-1 (有时在C/C++中这样做)作为打印所有条目的标志也是个坏主意，因为这样您就无法打印最后一个联系人(不调用len)。相反，只需使用None：try: index =int(输入(‘\n contact位置：’)，除了ValueError: index = None print_summary(address_book，index) def print_summary(address_book，index=None)：如果索引为None: contact in address_book: print(contact) index : print(address_book索引) print()，如您所见，我取消了您的显式打印，相反，让它成为Contact类的一部分，当被打印时，它看起来很漂亮。为此，您可以使用神奇的方法__str__，它应该返回实例的字符串表示:类联系人：.def __str__(self)：返回“/ ".join(Self.name，self.surname，self.number，self.email)
• 这个方法(以及__getitem__和__setitem__)是一个神奇的(或and )方法。在这里查看可以定义哪些其他特殊方法来提供自定义类的内置行为：https://rszalski.github.io/magicmethods/。