DevOps Classroom notes 18/Oct/2025

Building inventory

• We have implemented interactive cli refer here for change setRefer Here
• As of this changeset the warehouse items are stored in dictionary, once the program is stopped all entries are lost, We can save the items in a file

Liskovs substitution principle

• Refer Here for LSP

Duck typing

• If it walks like a duck and it quacks like a duck, then it must be a duck.

Python context manager

• Refer Here for context manager
• Refer Here for context managers added at last

Python file Manangemnt

• In python we can manage two types of files
• text
• binary
• Python standard library has built in method called as open which takes two arguments
  • path
  • mode

Using csv files to store warehouse itmes

• For each warehouse we will create a new csv file
• Any operations done on warehouse will lead to csv file changes
• Lets use pandas.
• Activate the virtual environments

pip install pandas # pip
uv pip install pandas # uv
uv add pandas # uv

• Refer Here for pandas tutorial
• Refer Here for samples