Ahora que hemos explorado varias aplicaciones del atributo __dict__, pongamos nuestro conocimiento en práctica construyendo una aplicación simple de gestión de contactos. Este mini-proyecto demostrará cómo usar __dict__ en un escenario del mundo real.
Nuestro gestor de contactos nos permitirá:
- Agregar contactos con varios atributos
- Buscar contactos
- Actualizar la información de contacto
- Eliminar contactos
- Exportar contactos a JSON
- Importar contactos desde JSON
- Crea un nuevo archivo llamado
contact_manager.py:
import json
import os
class Contact:
def __init__(self, name, email=None, phone=None, **kwargs):
self.name = name
self.email = email
self.phone = phone
## Add any additional attributes
for key, value in kwargs.items():
self.__dict__[key] = value
def update(self, **kwargs):
"""Update contact attributes"""
self.__dict__.update(kwargs)
def __str__(self):
"""String representation of the contact"""
attrs = []
for key, value in self.__dict__.items():
if value is not None:
attrs.append(f"{key}: {value}")
return ", ".join(attrs)
class ContactManager:
def __init__(self):
self.contacts = []
def add_contact(self, contact):
"""Add a new contact"""
self.contacts.append(contact)
print(f"Added contact: {contact.name}")
def find_contact(self, **kwargs):
"""Find contacts matching the criteria"""
results = []
for contact in self.contacts:
match = True
for key, value in kwargs.items():
## Skip if the contact doesn't have this attribute
if key not in contact.__dict__:
match = False
break
## Skip if the attribute value doesn't match
if contact.__dict__[key] != value:
match = False
break
if match:
results.append(contact)
return results
def update_contact(self, contact, **kwargs):
"""Update a contact's attributes"""
contact.update(**kwargs)
print(f"Updated contact: {contact.name}")
def delete_contact(self, contact):
"""Delete a contact"""
if contact in self.contacts:
self.contacts.remove(contact)
print(f"Deleted contact: {contact.name}")
else:
print("Contact not found.")
def export_contacts(self, filename):
"""Export contacts to a JSON file"""
contacts_data = []
for contact in self.contacts:
contacts_data.append(contact.__dict__)
with open(filename, 'w') as f:
json.dump(contacts_data, f, indent=2)
print(f"Exported {len(self.contacts)} contacts to {filename}")
def import_contacts(self, filename):
"""Import contacts from a JSON file"""
if not os.path.exists(filename):
print(f"File {filename} not found.")
return
with open(filename, 'r') as f:
contacts_data = json.load(f)
imported_count = 0
for data in contacts_data:
## Create a copy of the data to avoid modifying the original
contact_data = data.copy()
## Get the required parameters
name = contact_data.pop('name', None)
email = contact_data.pop('email', None)
phone = contact_data.pop('phone', None)
if name:
## Create a new contact with remaining attributes as kwargs
contact = Contact(name, email, phone, **contact_data)
self.contacts.append(contact)
imported_count += 1
print(f"Imported {imported_count} contacts from {filename}")
def print_all_contacts(self):
"""Print all contacts"""
if not self.contacts:
print("No contacts found.")
return
print(f"\nAll Contacts ({len(self.contacts)}):")
print("-" * 40)
for i, contact in enumerate(self.contacts, 1):
print(f"{i}. {contact}")
print("-" * 40)
## Let's test our contact manager
if __name__ == "__main__":
## Create a contact manager
manager = ContactManager()
## Add some contacts
manager.add_contact(Contact("John Doe", "john@example.com", "555-1234",
address="123 Main St", city="Boston"))
manager.add_contact(Contact("Jane Smith", "jane@example.com", "555-5678",
company="ABC Corp", role="Developer"))
manager.add_contact(Contact("Bob Johnson", "bob@example.com", "555-9012",
twitter="@bobjohnson", birthday="1985-03-15"))
## Print all contacts
manager.print_all_contacts()
## Find contacts
print("\nContacts with email ending with @example.com:")
for contact in manager.contacts:
if contact.email and contact.email.endswith("@example.com"):
print(f"- {contact.name}: {contact.email}")
## Use the find_contact method
print("\nFinding contacts by name:")
results = manager.find_contact(name="Jane Smith")
for contact in results:
print(f"Found: {contact}")
## Update a contact
if results:
manager.update_contact(results[0], phone="555-NEW-NUM", role="Senior Developer")
print(f"After update: {results[0]}")
## Export contacts to JSON
manager.export_contacts("contacts.json")
## Delete a contact
manager.delete_contact(results[0])
## Print all contacts after deletion
manager.print_all_contacts()
## Create a new manager and import contacts
print("\nCreating a new manager and importing contacts:")
new_manager = ContactManager()
new_manager.import_contacts("contacts.json")
new_manager.print_all_contacts()
- Ejecuta el archivo:
python3 contact_manager.py
Deberías ver la salida que muestra el gestor de contactos en acción, incluyendo la adición, búsqueda, actualización y eliminación de contactos, así como la exportación e importación de contactos hacia y desde un archivo JSON.
Ahora, mejoremos nuestro gestor de contactos agregando la capacidad de agregar campos personalizados para diferentes tipos de contactos:
- Crea un nuevo archivo llamado
extended_contact_manager.py:
from contact_manager import Contact, ContactManager
class BusinessContact(Contact):
def __init__(self, name, email=None, phone=None, company=None, role=None, **kwargs):
super().__init__(name, email, phone, **kwargs)
self.company = company
self.role = role
self.contact_type = "business"
class PersonalContact(Contact):
def __init__(self, name, email=None, phone=None, relationship=None, birthday=None, **kwargs):
super().__init__(name, email, phone, **kwargs)
self.relationship = relationship
self.birthday = birthday
self.contact_type = "personal"
class ExtendedContactManager(ContactManager):
def add_business_contact(self, name, email=None, phone=None, company=None, role=None, **kwargs):
contact = BusinessContact(name, email, phone, company, role, **kwargs)
self.add_contact(contact)
return contact
def add_personal_contact(self, name, email=None, phone=None, relationship=None, birthday=None, **kwargs):
contact = PersonalContact(name, email, phone, relationship, birthday, **kwargs)
self.add_contact(contact)
return contact
def find_by_contact_type(self, contact_type):
"""Find contacts by type (business or personal)"""
return self.find_contact(contact_type=contact_type)
def get_contact_details(self, contact):
"""Get detailed information about a contact"""
details = []
for key, value in contact.__dict__.items():
if value is not None:
if key == "contact_type":
details.append(f"Type: {value.capitalize()}")
else:
## Convert key from snake_case to Title Case
formatted_key = " ".join(word.capitalize() for word in key.split("_"))
details.append(f"{formatted_key}: {value}")
return "\n".join(details)
## Test the extended contact manager
if __name__ == "__main__":
## Create an extended contact manager
manager = ExtendedContactManager()
## Add some business contacts
manager.add_business_contact(
"Alice Johnson",
"alice@company.com",
"555-1111",
"XYZ Corp",
"Marketing Manager",
department="Marketing",
office_location="Building A, 3rd Floor"
)
manager.add_business_contact(
"Bob Williams",
"bob@startup.co",
"555-2222",
"StartUp Inc",
"CEO",
linkedin="linkedin.com/in/bobwilliams"
)
## Add some personal contacts
manager.add_personal_contact(
"Carol Davis",
"carol@gmail.com",
"555-3333",
"Friend",
"1990-05-15",
address="456 Oak St",
favorite_restaurant="Italian Place"
)
manager.add_personal_contact(
"Dave Wilson",
"dave@hotmail.com",
"555-4444",
"Family",
"1982-12-03",
emergency_contact=True
)
## Print all contacts
manager.print_all_contacts()
## Find contacts by type
print("\nBusiness Contacts:")
business_contacts = manager.find_by_contact_type("business")
for contact in business_contacts:
print(f"- {contact.name} ({contact.company})")
print("\nPersonal Contacts:")
personal_contacts = manager.find_by_contact_type("personal")
for contact in personal_contacts:
print(f"- {contact.name} ({contact.relationship})")
## Show detailed information for a contact
if business_contacts:
print("\nDetailed information for", business_contacts[0].name)
print(manager.get_contact_details(business_contacts[0]))
## Export contacts to JSON
manager.export_contacts("extended_contacts.json")
## Import contacts
new_manager = ExtendedContactManager()
new_manager.import_contacts("extended_contacts.json")
print("\nAfter importing:")
new_manager.print_all_contacts()
## Check if we can still identify contact types after import
imported_business = new_manager.find_by_contact_type("business")
print(f"\nImported {len(imported_business)} business contacts")
imported_personal = new_manager.find_by_contact_type("personal")
print(f"Imported {len(imported_personal)} personal contacts")
- Ejecuta el archivo:
python3 extended_contact_manager.py
Este gestor de contactos extendido demuestra cómo podemos usar el atributo __dict__ para crear estructuras de datos flexibles que pueden manejar diferentes tipos de contactos con atributos variables.
Paso 3: Crear una Interfaz de Línea de Comandos Simple
Finalmente, creemos una interfaz de línea de comandos simple para nuestro gestor de contactos:
- Crea un nuevo archivo llamado
contact_manager_cli.py:
from extended_contact_manager import ExtendedContactManager, BusinessContact, PersonalContact
def print_menu():
print("\n===== Contact Manager =====")
print("1. Add Business Contact")
print("2. Add Personal Contact")
print("3. List All Contacts")
print("4. Find Contact")
print("5. Update Contact")
print("6. Delete Contact")
print("7. Export Contacts")
print("8. Import Contacts")
print("9. Exit")
print("==========================")
def get_contact_details(contact_type):
"""Get contact details from user input"""
details = {}
## Common fields
details['name'] = input("Name: ")
details['email'] = input("Email (optional): ") or None
details['phone'] = input("Phone (optional): ") or None
## Type-specific fields
if contact_type == "business":
details['company'] = input("Company (optional): ") or None
details['role'] = input("Role (optional): ") or None
## Ask for custom fields
print("Add custom fields (leave empty to finish):")
while True:
field_name = input("Field name (or empty to finish): ")
if not field_name:
break
field_value = input(f"{field_name}: ")
details[field_name] = field_value
elif contact_type == "personal":
details['relationship'] = input("Relationship (optional): ") or None
details['birthday'] = input("Birthday (YYYY-MM-DD, optional): ") or None
## Ask for custom fields
print("Add custom fields (leave empty to finish):")
while True:
field_name = input("Field name (or empty to finish): ")
if not field_name:
break
field_value = input(f"{field_name}: ")
details[field_name] = field_value
return details
def select_contact(manager):
"""Let the user select a contact from the list"""
if not manager.contacts:
print("No contacts available.")
return None
print("\nSelect a contact:")
for i, contact in enumerate(manager.contacts, 1):
print(f"{i}. {contact.name}")
try:
selection = int(input("Enter number (0 to cancel): "))
if selection == 0:
return None
if 1 <= selection <= len(manager.contacts):
return manager.contacts[selection - 1]
else:
print("Invalid selection.")
return None
except ValueError:
print("Please enter a valid number.")
return None
def main():
manager = ExtendedContactManager()
while True:
print_menu()
choice = input("Enter your choice (1-9): ")
if choice == '1':
## Add Business Contact
print("\n-- Add Business Contact --")
details = get_contact_details("business")
name = details.pop('name')
email = details.pop('email')
phone = details.pop('phone')
company = details.pop('company')
role = details.pop('role')
manager.add_business_contact(name, email, phone, company, role, **details)
elif choice == '2':
## Add Personal Contact
print("\n-- Add Personal Contact --")
details = get_contact_details("personal")
name = details.pop('name')
email = details.pop('email')
phone = details.pop('phone')
relationship = details.pop('relationship')
birthday = details.pop('birthday')
manager.add_personal_contact(name, email, phone, relationship, birthday, **details)
elif choice == '3':
## List All Contacts
manager.print_all_contacts()
elif choice == '4':
## Find Contact
print("\n-- Find Contact --")
search_term = input("Enter name to search: ")
results = manager.find_contact(name=search_term)
if results:
print(f"\nFound {len(results)} contacts:")
for contact in results:
print(manager.get_contact_details(contact))
print("-" * 30)
else:
print("No contacts found with that name.")
elif choice == '5':
## Update Contact
print("\n-- Update Contact --")
contact = select_contact(manager)
if contact:
print("\nCurrent details:")
print(manager.get_contact_details(contact))
print("\nEnter new details (leave empty to keep current value):")
updates = {}
for key, value in contact.__dict__.items():
if key != "contact_type": ## Don't allow changing the contact type
new_value = input(f"{key} [{value}]: ")
if new_value and new_value != str(value):
updates[key] = new_value
manager.update_contact(contact, **updates)
print("\nContact updated.")
elif choice == '6':
## Delete Contact
print("\n-- Delete Contact --")
contact = select_contact(manager)
if contact:
confirm = input(f"Are you sure you want to delete {contact.name}? (y/n): ")
if confirm.lower() == 'y':
manager.delete_contact(contact)
elif choice == '7':
## Export Contacts
print("\n-- Export Contacts --")
filename = input("Enter filename (default: contacts.json): ") or "contacts.json"
manager.export_contacts(filename)
elif choice == '8':
## Import Contacts
print("\n-- Import Contacts --")
filename = input("Enter filename: ")
manager.import_contacts(filename)
elif choice == '9':
## Exit
print("\nThank you for using Contact Manager!")
break
else:
print("Invalid choice. Please try again.")
if __name__ == "__main__":
main()
- Ejecuta la aplicación CLI:
python3 contact_manager_cli.py
- Intenta agregar algunos contactos, buscar contactos, actualizar contactos y exportar/importar contactos usando la interfaz de línea de comandos.
Este mini-proyecto demuestra cuán poderoso puede ser el atributo __dict__ al construir aplicaciones basadas en datos flexibles en Python. El gestor de contactos permite campos personalizados en los contactos, la serialización hacia y desde JSON, y la fácil gestión de diferentes tipos de contactos, todo aprovechando el atributo __dict__ para gestionar dinámicamente los datos de la instancia.
A través de este proyecto, has aprendido a:
- Usar
__dict__ para almacenar y recuperar atributos de objetos
- Crear clases flexibles que pueden manejar atributos variables
- Serializar y deserializar objetos hacia y desde JSON
- Construir una aplicación simple de línea de comandos que aprovecha los atributos dinámicos
Estas habilidades se pueden aplicar a muchas aplicaciones Python del mundo real, desde herramientas de procesamiento de datos hasta aplicaciones web e integraciones de API.
