Programming is about using lower-level functionality to create higher-level functionality. In general, any programming language is a collection of functions that in turn build upon functions provided by the operating system. You must master the art of building your own code with the help of existing functionality, instead of reinventing the wheel! Keyword Arguments Functions … Read more
If you’re like me, you want to come to the heart of an issue fast. Here’s the 1-paragraph summary of the enumerate() function—that’s all you need to know to get started using it: Python’s built-in enumerate(iterable) function allows you to loop over all elements in an iterable and their associated counters. Formally, it takes an … Read more
Python’s built-in divmod(a, b) function takes two integer or float numbers a and b as input arguments and returns a tuple (a // b, a % b). The first tuple value is the result of the integer division a//b. The second tuple is the result of the remainder, also called modulo operation a % b. … Read more
Challenge: How to create a multi-line string in Python? In this tutorial, I’ll show you four methods to create and maintain multi-line strings in Python. The most Pythonic ones are the first two methods with triple single quotes ”’ … ”’ or triple double quotes “”” … “”” that wrap a string across multiple lines. … Read more
Large companies analyze massive amounts of data coming from various sources such as social nets, weblogs, or customers. An important class of data analytics concerns large-scale set operations. Suppose you have two customer data sets A and B. Set A contains all customers who bought in 2017. Set B contains all customers who bought in … Read more
Modifying a sequence while iterating over it can cause undesired behavior due to the way the iterator is build. To avoid this problem, a simple solution is to iterate over a copy of the list. For example, you’ll obtain a copy of list_1 by using the slice notation with default values list_1[:]. Because you iterate … Read more
NumPy is a popular Python library for data science. Numpy focuses on array, vector, and matrix computations. If you work with data, you cannot avoid NumPy. So learn it now and learn it well. In this tutorial, you’ll learn how to calculate the Hadamard Product (= element-wise multiplication) of two 1D lists, 1D arrays, or … Read more
If used without argument, Python’s built-in dir() function returns the function and variable names defined in the local scope—the namespace of your current module. If used with an object argument, dir(object) returns a list of attribute and method names defined in the object’s scope. Thus, dir() returns all names in a given scope. Usage Learn … Read more
Challenge: How to find a given value in a sorted list? Example: Say, you have a sorted list: Your goal is to find the index of the element 103 in the list. Do you have to check all elements to do this? Well, only if you used the … Naive List Search Algorithm A naive … Read more
Python’s built-in dict() function creates and returns a new dictionary object from the comma-separated argument list of key = value mappings. For example, dict(name = ‘Alice’, age = 22, profession = ‘programmer’) creates a dictionary with three mappings: {‘name’: ‘Alice’, ‘age’: 22, ‘profession’: ‘programmer’}. A dictionary is an unordered and mutable data structure, so it … Read more
Python’s built-in getattr(object, string) function returns the value of the object‘s attribute with name string. If this doesn’t exist, it returns the value provided as an optional third default argument. If that doesn’t exist either, it raises an AttributeError. An example is getattr(porsche, ‘speed’) which is equivalent to porsche.speed. Usage Learn by example! Here’s an … Read more
Python’s built-in setattr(object, string, value) function takes three arguments: an object, a string, and an arbitrary value. It sets the attribute given by the string on the object to the specified value. After calling the function, there’s a new or updated attribute at the given instance, named and valued as provided in the arguments. For … Read more