How to Build a Search Engine from Scratch in Python (No External Packages)

A pure Python implementation of a TF-IDF based English search engine is described, covering document processing, index construction, query processing, and result ranking. The system uses Python's standard library and stores the inverted index in CSV format. Key components include tokenization, stop word removal, TF-IDF calculation, and relevance scoring. The article provides code examples and explanations of core concepts. While this basic implementation has limitations, it offers insights into search engine fundamentals and can serve as a foundation for more advanced systems.