Quick recall
Python is dynamically typed because types are checked at runtime, and strongly typed because values do not silently coerce across unrelated types.
Encapsulation organizes state and behavior, abstraction hides unnecessary detail, polymorphism lets different objects satisfy the same interface, and composition often keeps designs looser than inheritance.
Python strings are Unicode text, while bytes are encoded binary data that must be encoded or decoded at boundaries.
Catch narrow exceptions, add context, and avoid swallowing failures silently.
Python file work combines open modes like read, write, and append with text or binary handling, and context managers ensure resources close correctly.
Functions are first-class values in Python, so you can pass them around, return them, and build closures or higher-order helpers.
The GIL lets only one Python thread execute Python bytecode at a time in CPython.
Python primarily uses reference counting, with cyclic garbage collection to clean objects that reference each other.
Inheritance reuses behavior, overriding customizes it, `super()` follows the method resolution order, and multiple inheritance works only if the MRO stays coherent.
Instance methods work with object state, class methods work with the class, static methods are utility functions inside the namespace, properties expose attribute-style access, and dataclasses reduce boilerplate.
Python source is usually compiled to bytecode first, then executed by the interpreter's virtual machine.
An iterable can produce an iterator, an iterator yields values one at a time, generators are a compact way to build iterators, and advanced generator methods can push values or exceptions back in.