**LangChain Chains:** - Fixed, predefined sequence of steps - The flow is hardcoded by the developer - Deterministic — same input → same...

A vector database stores data as high-dimensional vectors (embeddings) and enables fast similarity search. **Why it's needed:** LLMs unders...

Python uses two mechanisms for memory management: **1. Reference Counting (primary):** Every object has a reference count. When it reaches ...

A generator is a function that yields values one at a time instead of returning them all at once — saving memory. **Regular function vs G...

Due to Python's GIL (Global Interpreter Lock), threads can't run Python code in parallel — only one thread executes at a time. **Multithr...

Here is a simple RAG chatbot using LangChain: ```python from langchain_openai import ChatOpenAI, OpenAIEmbeddings from langchain_community....

Here are the most commonly asked Python questions in data science interviews: 1. Difference between list, tuple, and set 2. Explain generat...

Python alone is NOT enough, but it's the most important skill. You need: 1. **Python** (Pandas, NumPy, Scikit-learn, Matplotlib) 2. **SQL**...

Pandas is a Python library for data manipulation and analysis. It provides two main data structures: **Series** — 1D labelled array **Dat...

LangChain is a framework for building applications with Large Language Models (LLMs). It provides: - **Chains** — link multiple LLM calls...

**==** checks value equality — are the values the same? **is** checks identity — are they the exact same object in memory? ```python a ...

List comprehension is a concise way to create lists. ```python # Traditional way squares = [] for x in range(10): squares.append(x**2) ...

A decorator is a function that wraps another function to extend its behaviour without modifying it. ```python def my_decorator(func): d...

Python uses automatic memory management through a private heap and a garbage collector. 1. **Reference counting** — every object tracks h...

Python is one of the most commonly asked Python basics interview questions. A **list** is mutable (you can change its elements), while a **...