How to Find Multiple Occurrences of a String Within a String in Python?

Problem Formulation: Given a longer string and a shorter string. How to find all occurrences of the shorter string in the longer one? Consider the following example: Longer string: ‘Finxters learn Python with Finxter’ Shorter string: ‘Finxter’ Result: [‘Finxter’, ‘Finxter’] Optionally, you may also want to print the positions where the shorter string arise in … Read more

How to Split a Byte String into Lines?

Problem Formulation: Given a byte string that contains new-line characters ‘\n’. How to split the byte string into a list of lines? Example: You want to transform the byte string b’your\nbyte\nstring’ into the list of byte strings [b’your’, b’byte’, b’string’] using b’\n’ as a newline separator. Given: b’your\nbyte\nstring’ Goal: [b’your’, b’byte’, b’string’] Solution: To split … 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

How To Cut A String In Python?

Problem: Given a string; how to split/cut the string and extract the required characters? In this article, we will be discussing some interesting scenarios which allow us to split or cut a string and extract the necessary portion of the string that we need. Let us dive into each example/scenario and have a look at … Read more

Python ord() Function

The Python ord() function takes a character (=string of length one) as an input and returns the Unicode number of this character. For example, ord(‘a’) returns the Unicode number 97. The inverse function of ord() is the chr() function, so chr(ord(‘a’)) returns the original character ‘a’. Here are three examples of passed Unicode characters transformed … Read more

Python Join Arguments and String Concatenation

Problem: Write a function that joins an arbitrary number of string arguments with a given separator. Example: Given the string arguments “A”, “B”, and “C” and the string separator “-“. Join them to the concatenated string “A-B-C”. Solution: The following code creates a Python function concat() that takes an arbitrary number of arguments, packs them … 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

String Slicing in Python

String slicing is a concept to carve out a substring from a given string. Use slicing notation s[start:stop:step] to access every step-th element starting from index start (included) and ending in index stop (excluded). All three arguments are optional, so you can skip them to use the default values (start=0, stop=len(string), step=1). For example, the … Read more