Tell me about the Garbage Collector in Python — how does it work?

Memory management in Python is based on reference counting and an additional garbage collector for cyclic references.

Main points:

• Reference counting: Each object in Python maintains a reference count — the number of active references to it. When the count drops to zero, the object is immediately deleted and memory is freed.

• Cyclic references problem: If objects reference each other but are not used, reference counting cannot delete them because their counts are not zero.

• Garbage collector (GC): To solve the cycle problem, the gc module is used, which periodically searches for object cycles that are inaccessible from the program and deletes them.

• How GC works: It divides objects into generations (0, 1, 2) and checks younger objects more frequently. This optimizes performance.

Example of manually invoking the collector:

import gc

# Invoke garbage collection
collected = gc.collect()
print(f"Objects collected: {collected}")

Thus, Python combines fast reference counting with periodic cycle detection for efficient memory management.