How would you deploy a Django application to a production environment, considering scalability and security?
- Deploy the Django application without a reverse proxy. Implement security measures within Django views and models. Use a basic firewall.
- Host the application on a shared hosting platform. Use self-signed certificates for SSL/TLS. Deploy only a single server instance. Enable root access for easier management.
- Use a single server with Docker containers for isolation. Disable SSL/TLS for faster performance.
- Use a web server like Nginx or Apache as a reverse proxy in front of Gunicorn or uWSGI. Implement SSL/TLS for secure communication. Utilize a load balancer to distribute traffic across multiple server instances. Harden the server by following security best practices.
Deploying a Django application for production involves multiple steps, including setting up a reverse proxy, securing communications with SSL/TLS, load balancing for scalability, and following security best practices.
How would you design a class that shouldn’t be instantiated?
- By declaring the class as abstract.
- By defining a private constructor.
- By making the class private.
- By using the final keyword.
To prevent a class from being instantiated, you can define a private constructor. When the constructor is private, it cannot be called from outside the class, effectively preventing object creation.
How would you enable Cross-Origin Resource Sharing (CORS) in a Flask application?
- CORS is enabled by default in Flask
- Modify the browser's settings
- Use the "@cross_origin" decorator
- Use the Flask-CORS extension
You can enable CORS in Flask by using the Flask-CORS extension. The other options are not the recommended way to enable CORS in Flask.
How would you enable Cross-Origin Resource Sharing (CORS) in a Flask application?
- Add Access-Control-Allow-Origin header to each route manually.
- CORS is not applicable to Flask applications.
- Set CORS_ENABLED = True in the Flask app configuration.
- Use the @cross_origin decorator from the flask_cors extension.
To enable CORS in a Flask application, you typically use the @cross_origin decorator provided by the flask_cors extension. This allows you to control which origins are allowed to access your API.
How does a metaclass differ from a class in Python?
- A class can be instantiated multiple times.
- A metaclass can be instantiated multiple times.
- A metaclass defines the structure of a class, while a class defines the structure of an instance.
- A metaclass is an instance of a class.
In Python, a metaclass is a class for classes. It defines the structure and behavior of classes, while a regular class defines the structure of instances created from it. A metaclass is used to customize class creation and behavior.
How is a generator function different from a normal function in Python?
- A generator function is a built-in Python function
- A generator function is defined using the generator keyword
- A generator function returns multiple values simultaneously
- A generator function yields values lazily one at a time
A generator function differs from a normal function in that it uses the yield keyword to yield values lazily one at a time, allowing it to generate values on-the-fly without consuming excessive memory.
How would you analyze the reference count of an object in Python to debug memory issues?
- Reference count analysis is not relevant for debugging memory issues in Python.
- Use the gc module to manually increment and decrement the reference count.
- Utilize the sys.getrefcount() function to inspect the reference count.
- Write custom code to track object references in your application.
You can use the sys.getrefcount() function to inspect the reference count of an object in Python. It's a built-in way to gather information about an object's reference count. Options 1 and 4 are not recommended practices, and Option 3 is incorrect since reference count analysis is indeed relevant for debugging memory issues.
How can you implement a stack such that you can retrieve the minimum element in constant time?
- It's not possible
- Using a linked list
- Using a priority queue
- Using an additional stack
You can implement a stack that allows retrieving the minimum element in constant time by using an additional stack to keep track of the minimum values. Whenever you push an element onto the main stack, you compare it with the top element of the auxiliary stack and push the smaller of the two. This ensures constant-time retrieval of the minimum element.
How can you integrate a Python back-end with a Single Page Application (SPA) framework like Angular or React?
- Create RESTful APIs
- Embed Python code in SPA components
- Use SOAP protocols
- Utilize Django templates
To integrate a Python back-end with an SPA framework like Angular or React, you should create RESTful APIs. This allows the front-end to communicate with the back-end through standardized HTTP requests, enabling data retrieval and manipulation.
How can you invoke the method of a superclass from a subclass?
- By calling the superclass method directly
- By importing the superclass module
- By using the extends keyword
- Using the super() function
In Python, you invoke the method of a superclass from a subclass using the super() function. This allows you to access and call methods from the superclass within the subclass.