## How Python Manages Memory Python manages memory automatically using a combination of two subsystems: **Reference Counting** and the **Generational Garbage Collector**. ### 1. Reference Counting Every object in CPython contains a field called `ob_refcnt`, which tracks how many references point to it. - When a variable is bound, the count increases. - When a reference goes out of scope or is deleted, the count decreases. - If the count drops to zero, Python instantly deallocates the memory. ### 2. Generational Garbage Collection Reference counting cannot detect reference cycles (e.g., Object A references Object B, and Object B references Object A, but neither is accessible from the root scope). - Python uses a cycle detector that groups objects into three generations (Gen 0, Gen 1, Gen 2). - Newer objects go to Gen 0. If they survive a GC cycle, they move to Gen 1, and eventually Gen 2. - Checks are run periodically. Gen 0 is checked frequently, while Gen 2 is checked rarely.