Satori Komeiji's Programming Classroom

Aug 29, 2024 · Fundamentals

How Python Dictionaries Resize: The Full Expansion Process

The article explains Python's dict resizing mechanism, detailing when the hash table grows (when used entries reach two‑thirds of capacity), how the new size is chosen as the smallest power‑of‑two ≥ ma_used × 3, and the exact steps the interpreter takes to reallocate and rebuild the underlying key and entry arrays.