In Python we care about the behavior of an object more than the type of an object. We say, "if it looks like a duck and walks like a duck, it's a duck." This idea is called duck typing.| www.pythonmorsels.com
Sets and dictionaries are powered by hashability. And hashable objects tend to be immutable.| www.pythonmorsels.com
Sequences are iterables that have a length. Sequences are ordered collections (they maintain the order of their contents). The most common sequences built-in to Python are string, tuple, and list.| www.pythonmorsels.com
Python's built-in enumerate function is the preferred way to loop while counting upward at the same time. You'll almost always see tuple unpacking used whenever enumerate is used.| www.pythonmorsels.com