ChrisChallenge: Given a string ‘/path/to/file.py’. How to check whether a file exists at ‘/path/to/file.py’, without using the try and except statements for exception handling? # What You Want! if exists(‘/path/to/file.py’): … # Do something Solution: To check whether a file exists at a given path, Run from pathlib import Path to import the path object, … Read more
A set is an unordered collection of elements. Each element can exist at most once in a set. There are no duplicate elements. Goal: How to intersect to Python sets? Solution: set_a & set_b The set intersection operator set_a & set_b intersects two sets, i.e., creates a new set with elements that exist in both … Read more
The map() function transforms one or more iterables into a new one by applying a “transformator function” to the i-th elements of each iterable. The arguments are the transformator function object and one or more iterables. If you pass n iterables as arguments, the transformator function must be an n-ary function taking n input arguments. … Read more
Like most coders, I regularly consult a search engine—yeah, as if there were many good options ;)—to learn about parameter lists of specific Python functions. If you truly stand on the shoulders of giants, and leverage the powerful Python libraries developed by some of the best coders in the world, studying the API of existing … Read more
There are three problem variants of finding the maximum value in a Python dictionary: In the following, you’ll learn how to solve those in the most Pythonic way: Find Maximum Value & Return Only Value The output is: Find Maximum Value & Return (Key, Value) Pair The output is: Find Maximum Value & Return Only … Read more
To sort a dictionary by key in Python, use the dictionary comprehension expression {key:dict[key] for key in sorted(dict)} to create a new dictionary with keys in sorted order. You iterate over all keys in sorted order, obtain their associated values with rank[key], and put them into a new dictionary. Python dictionaries preserve the order—even if … Read more
Python Boolean variables are set to either the True or False keywords. Both keywords require an Upper Case letter—lowercase letters are interpreted as normal variable or function names, so you could set true = True. A variable is of type Boolean if type(variable) results in the output <class ‘bool’>. You can convert any object to … Read more
Python’s locals() function returns a dictionary of name –> object mappings. The names are the ones defined in the current local scope, i.e., defined within the current module, class, method, or function—whatever the most local scope is. The objects are the values associated to these names. For example, if you set variable x = [1, … Read more
Python’s built-in “dunder” function __import__() allows you to import a library by name. For example, you may want to import a library that was provided as a user input, so you may only have the string name of the library. For example, to import the NumPy library dynamically, you could run __import__(‘numpy’). In this tutorial, … Read more
Challenge: This article shows how to sort a Python list using the key argument that takes a function object as an argument. Quick Solution: You can use the lambda function to create the function on the fly as shown in the following example: Explanation: The code uses the key argument and passes a lambda function … Read more
Knowing the basics is what sets apart the great from the intermediate coders. In other words, a simple and effective way to grow your skills is to learn the basics of computer science. Python Pathfinder Algorithm In this tutorial, you’ll learn about the pathfinder algorithm that recursively determines whether there’s a direct or indirect path … Read more
A piece of Python code is a waste of time and resource without communicating with the real world. In this tutorial, you’ll master the humble, but powerful, Python print() function. Python’s built-in print() function prints a string representation of any number of objects to the standard output. The print() function has many advanced arguments to … Read more