Unlike traditional C-style for loops, Python's for loops don't have indexes. It's considered a best practice to avoid reaching for indexes unless you really need them.| www.pythonmorsels.com
Python's dictionaries act as lookup tables which map keys to their values.| www.pythonmorsels.com
Python's list comprehensions are special-purpose tools for taking an old iterable, looping over it, and making a new list out of it.| www.pythonmorsels.com
List comprehensions make lists; generator expressions make generators. Generators are lazy single-use iterables which generate values as you loop over them.| www.pythonmorsels.com
An iterable is anything you're able to iterate over (iter-able). Iterables can be looped over and anything you can loop over is an iterable. Not every iterable is indexable or has a length.| www.pythonmorsels.com
Source code: Lib/collections/__init__.py This module implements specialized container datatypes providing alternatives to Python’s general purpose built-in containers, dict, list, set, and tuple.,,...| Python documentation