Python re.findall

The `re.findall()` function is a method in Python's built-in `re` module used to search for all non-overlapping occurrences of a regular expression pattern in a given string and return a list of all matched substrings.

The syntax of `re.findall()` is as follows:

re.findall(pattern, string, flags=0)

Here, `pattern` is the regular expression pattern to search for, `string` is the input string to search in, and `flags` (optional) is an integer value that can modify the behavior of the regular expression pattern.

The `re.findall()` function returns a list containing all the matched substrings in the order they were found in the input string. If there are no matches, an empty list is returned.

Example usage:

import re

text = "The quick brown fox jumps over the lazy dog"
matches = re.findall(r"\b\w{3}\b", text)

print(matches)
# Output: ['The', 'fox', 'the', 'dog']

In this example, the regular expression pattern `\b\w{3}\b` searches for all three-letter words in the input string `text`. The `re.findall()` function returns a list of all matched substrings, which are the words "The", "fox", "the", and "dog".