A Tree is any data structure that follows some particular rules. The tree must have exactly one root node. If you have two root nodes, what you actually have is two trees. One tree has one root, and one root equals one tree. Additionally, each node can have any number of child nodes or may have zero children, in which case we call that node a leaf.…
The deque data structure is unique in comparison to other linear data structures. To begin, a deque stands for double-ended queue where we take the D, the E, and the first three letters of queue and put them all together to create this new word called deque. It is pronounced like Deck. It’s an abstract data type that resembles both a stack and a queue. Deques can hold a collection of items and order is semi preserved in a deque.…
Queues are a linear abstract data type with some key differences between stacks. Queues hold a collection of items in the order in which they were added. Items that are added to the back of a queue and removed from the front of the queue. You run into queues all the time. The last time you went grocery shopping you likely had to wait in a line to check out.…
A stack holds a collection of items in the order in which they were added. You can only add items to and remove items from the top of a stack. If you think of a stack as a stack of pancakes, you can only add to the top of the pancake stack and remove it from the top of the pancake stack. This is a last-in-first-out system because the most recent item you add is the one that’s going to get removed next.…
A dataframe in Pandas is a two-dimensional array that has rows and columns. The dataframe is the primary component of the popular Pandas Python library. Pandas is an open-source Python library that provides high performance, easy-to-use data structures, and analysis tools. Pandas runs on top of Python NumPy, and we’ll take a look at how to get started with dataframes in Pandas for this tutorial.
Before we look at dataframes in Pandas, let’s do a quick comparison of NumPy and Pandas.…
A decorator in Python is a callable that takes another function as an argument and adds additional behavior to that function without explicitly modifying the function. A decorator has the ability to run additional code before and after each call to a function that it wraps. This means that decorators can access and modify input arguments and return values. The advantage of a decorator is that it will change the behavior of that function without permanently modifying it.…
You may have seen a curious syntax in some Python programs that includes a string like if __name__ == “__main__”: main(). Some might refer to it as the def main if name main idiom. The if __name__ == “__main__” has some benefits that you may want to consider, especially if you are a fan of single-file Python scripts. In this tutorial about if __name__ == “__main__”, we’ll take a look at what this pattern offers, and why it is smart to use it.…