John questions

• Why does Rust allow upgrading/downgrading mutability?
• How do I fix the return type of a Django model manager's method?
• Is there a difference between using a reference, and using an owned value in Rust?
• How can you prefix a Python pathlib.Path with another path?
• Can I use ABC and Django Abstract classes together in Python?
• How can I install DistUtilsExtra on Python compiled from sources?
• How does a Python listening socket get setup?
• Why can you specify multiple generic lifetimes on functions?
• What is the scope of a trait implementation on a type from the standard library in Rust?
• How to prevent deletion of Django model from Django Admin, unless part of a cascade

John answers