How to Convert a String List to an Integer List in Python

The most Pythonic way to convert a list of strings to a list of ints is to use the list comprehension [int(x) for x in strings]. It iterates over all elements in the list and converts each list element x to an integer value using the int(x) built-in function. This article shows you the simplest … Read more

How to Convert a String List to a Float List in Python

The most Pythonic way to convert a list of strings to a list of floats is to use the list comprehension floats = [float(x) for x in strings]. It iterates over all elements in the list and converts each list element x to a float value using the float(x) built-in function. This article shows you … Read more

How to Convert an Integer List to a Float List in Python

The most Pythonic way to convert a list of integers ints to a list of floats is to use the list comprehension expression floats = [float(x) for x in ints]. It iterates over all elements in the list ints using list comprehension and converts each list element x to a float value using the float(x) … Read more

How to Get an HTML Page from a URL in Python?

This tutorial shows you how to perform simple HTTP get requests to get an HTML page from a given URL in Python! Problem Formulation Given a URL as a string. How to extract the HTML from the given URL and store the result in a Python string variable? Example: Say, you want to accomplish the … Read more

How to Print an Integer with Commas as Thousands Separators in Python?

Problem Formulation: Given an integer number. How to convert the integer to a string representation for printing or other use that has thousand separators? Example: Given an integer number 1000000. You want the string representation ‘1,000,000’. Method 1: f-Strings Using the modern f-strings is, in my opinion, the most Pythonic solution to add commas as … Read more

How to Remove Everything After the Last Character in a String?

Problem Formulation Given string s, and character c. How to remove all characters in s after the first occurrence of c? Example Given: – string s = ‘hello world’, and – empty space character c = ‘ ‘. Desired result: ‘hello’ Method 1: string.index() + slicing To remove everything after the first occurrence of character … Read more

The Fibonacci Series in Python

The Fibonacci series was discovered by the Italian mathematician Leonardo Fibonacci in 1202 and even earlier by Indian mathematicians. The series appears in unexpected areas such as economics, mathematics, art, and nature. Algorithm Sketch In the following, we give a simple algorithm to calculate the Fibonacci numbers. The series starts with the Fibonacci numbers zero … Read more

Python exec() — A Hacker’s Guide to A Dangerous Function

Python’s exec() function executes the Python code you pass as a string or executable object argument. This is called dynamic execution because, in contrast to normal static Python code, you can generate code and execute it at runtime. This way, you can run programmatically-created Python code. Have you ever wondered about the limits of a … Read more

Why Slicing With Index Out Of Range Works In Python?

Python slicing means to access a subsequence of a sequence type using the notation [start:end]. A little-known feature of slicing is that it has robust end indices. Slicing is robust even if the end index is greater than the maximal sequence index. The slice just takes all elements up to the maximal element. If the … Read more

Python String Concatenation Without ‘+’

When I first saw this, I was sure it’s a bug. Well—it’s a feature! In today’s short article, you’ll learn about a small Python trick that I call “string concatenation without +”. Let’s start with some code! Plus vs. Adjacent String Literal Concatenation There are two ways to concatenate string literals in Python: Using the … Read more