Python

Python Generators

Python generators allow you to easily create efficient sequences of values using iterators. They can be implemented with special functions called generator functions, which use the yield keyword to yield values one at a time, rather than returning them all at once. Generators can also be created with generator expressions, which are similar to list comprehensions but produce values lazily as well.

Python Closures

Python closures are functions bundled up with variables they access in outer, non-local scopes of enclosing functions. Closures are essential when inner functions need access to variables from their enclosing scope because without them, these variables would be lost once the enclosing function completes execution.

The Python nonlocal Keyword

The Python nonlocal keyword is used to access and modify variables from an outer (but not global) scope in nested functions (i.e. non-local variables). It tells Python that a variable assigned in a nested function should refer to a variable in the nearest enclosing scope that is not global. Otherwise, Python will create a new variable in the local scope of the nested function.

The Python global Keyword

The global keyword in Python is used to access and modify global variables from within a function's local scope. It tells Python that a variable assigned in a function should refer to a global variable. Otherwise, Python will create a local variable of the same name.

Understanding Python Scopes

A scope is the extent of visibility and accessibility of named entities such as variables, functions, and classes, within a program. It determines where in your code you can access a particular name or identifier. There are three types of Python scopes: build-in, global, and local.