Python Programming

Collections Module - defaultdict

• collections.defaultdict takes a type not a value
• It will initialize based on the default value for that type
• Common mistake: passing a value instead of a callable type
• Example: defaultdict(list) not defaultdict([])
• Cleaner than manually checking if keys exist before accessing

Version Control

Git Commands and Tricks

• git log --format="%H" -n 1 | cat outputs the last commit ID
• Useful for scripting and automation
• The cat ensures the output is properly formatted
• %H format specifier gives the full commit hash
• -n 1 limits to the most recent commit

Cloud Infrastructure and DevOps

AWS EC2 Free Tier

• EC2 has a Free tier! I can request a bunch of machines here
• Great for learning and experimenting with cloud infrastructure
• Limited resources but sufficient for development and testing
• Good entry point for understanding cloud computing concepts

Juju - Multi-Cloud Orchestration

• Juju is a tool that helps manage server providers, whether they are GCP, AWS, your own servers or Azure, among others
• Gives you one way to start, setup and run your servers across different cloud providers
• Abstracts away cloud provider differences
• Enables consistent deployment across hybrid and multi-cloud environments

Juju Configuration System

• Juju’s configurations are called charms
• These are written in Python
• Charms define how services should be deployed and configured
• Reusable deployment patterns for common software stacks
• Community-maintained charm store with pre-built configurations