goitneo-python-hw2-MCS3

Created for submission of the homework assignment Nr 2. Tier 1. Python Programming: Foundations and Best Practices

Structure of the project

Using flat structure of the project because setup of relative or absolute imports took too much time Folder hw2 contains:

• task 1: bot_assistant.py
• task 2: address_book_classes.py
• contacts.json with several contacts stored to be used a a storage for bot_assistant
• constants.py storing constants used in bot_assistant.py
• exceptions.py with definitions of custom exceptions for both tasks

Task 1

For the CLI created in the HW1 add custom error handling using decorator functions. I've created custom exceptions DuplicateEntry and ValueNotFound that accept username as parameter and are raised when either username has already been added or such username hasn't been stored respectively. FileNotFoundError is a built-in error that I'm using when the file where the contacts are stored isn't there or is empty. ValueError is a built-in error that I'm catchning whenever parsing of the command hasn't been successful, raising a custom InvalidCommand exception that accepts optional command name argument to handle all such cases in one place.

# decorator for exception handling
def input_error(func):
  def inner(*args, **kwargs):
      try:
          return func(*args, **kwargs)
      except DuplicateEntry as error:
          return f"We alreay have a contact with name {error.name}"
      except ValueNotFound as error:
          return f"No contact for name {error.name} found"
      except FileNotFoundError:
          # if the file is empty there are no contacts to show
          return "We haven't stored any contacts yet"
  return inner

# example of using the decorator
@input_error
def add_contact(args, contacts):
    name, phone = args
    contacts[name] = phone
    return "Contact added."

Task 2

Create classes for future storing of the contact information of the users:

• Field: basic class for the creation of the fields in the address book
• Name: class storing a name of the contact, name is obligatory
• Phone: class for storing phone number, has a format validation - 10 digits
• Record: class for storing the information about the contact including name and list of phone numbers. Supported operations:
  • adding phone numbers
  • deleting phone numbers
  • editing phone numbers
  • searching phone number
• AddressBook: class for storing and managing records. Supported operations:
  • adding records
  • searching records by name
  • deleting records by name