Python Use a Regex to Filter Data
Regular expressions, often referred to as "regex" or "regexp," are a powerful tool for working with text data in Python. They allow you to search for and manipulate text patterns within strings. In this tutorial, we will explore how to use regular expressions to filter data in Python.
Before you begin, make sure you have Python installed on your system. You can download it from the official Python website. Additionally, Python's built-in re module is used for working with regular expressions, so there is no need to install any third-party libraries.
Regular expressions are a sequence of characters that define a search pattern. They are extremely versatile and can be used for tasks such as searching, extracting, validating, and replacing text. A regex pattern is constructed using a combination of ordinary characters and special characters that have predefined meanings.
Here are some commonly used special characters in regex:
Python provides the re module for working with regular expressions. To use it, you need to import the module:
Here is an example of how to use the re module to filter data:
In this example, we use the re.findall() function to find all the 5-letter words in the given text. The r before the pattern is used to specify a raw string, which is often recommended for regex patterns to avoid escape character conflicts.
The re.search() function searches for a match anywhere in the string and returns the first occurrence.
The re.match() function checks if the regex pattern matches at the beginning of the string.