Python Regex: re.search() VS re.findall()
Last Updated : 28 May, 2025
Python’s re module provides powerful tools to search, match and manipulate text using regular expressions. Two commonly used functions are re.search(), which finds the first occurrence of a pattern in a string and re.findall(), which retrieves all matches of a pattern throughout the string. Understanding how each works will help you effectively handle text processing tasks.
What is re.search() ?
re.search() function scans through a string, looking for the first location where the regular expression pattern produces a match. It returns a match object if a match is found, otherwise returns None.
Example:
Python import re s = "My favorite fruits are apple, banana, and mango." res = re.search(r'\b\w*a\b', s) if res: print(res.group()) else: print("Not found.") Explanation:
- re.search(r'\b\w*a\b', s) looks for the first word in the string that ends with the letter 'a'.
- pattern \b\w*a\b means the word must start and end at a word boundary (\b), contain any number of word characters (\w*) and end specifically with 'a'.
What is re.findall() ?
re.findall() function returns all non-overlapping matches of a pattern in a string as a list of strings. If the pattern has capturing groups, it returns a list of tuples.
Python import re s = "My favorite fruits are apple, banana, and mango." res = re.findall(r'\b\w*a\b', s) print(res)
Explanation:
- re.findall(r'\b\w*a\b', s) finds all words in the string that end with the letter 'a'.
- pattern \b\w*a\b means the word must start and end at a word boundary (\b), contain any number of word characters (\w*) and end specifically with 'a'.
Example with capturing Groups
Capturing groups in regular expressions are used to extract specific parts of the matched text. You create a group by placing part of the pattern inside parentheses ().
Example 1: In this example, we want to extract the price (just the number) after the word Price by using re.search().
Python import re s = "Price: $30, Discount: $5" res = re.search(r'Price: \$(\d+)', s) if res: print(res.group(1))
Explanation:
- re.search(r'Price: \$(\d+)', s) looks for the first occurrence of the word "Price:" followed by a dollar sign $ and then one or more digits.
- pattern Price: \$(\d+) uses parentheses () to create a capturing group that extracts just the number after "Price: $".
Example 2: Now, suppose you want to extract all numbers that come after a dollar sign ($) in the sentence. You can use re.findall() for this.
Python import re s = "Price: $30, Discount: $5" res = re.findall(r'\$(\d+)', s) print(res)
Explanation:
- re.findall(r'\$(\d+)', s) searches the entire string for all numbers that come after a dollar sign $.
- pattern \$(\d+) uses a capturing group (\d+) to extract one or more digits following each $ symbol.
Difference between research() and re.findall()
Both functions are used to find patterns in text, but they serve different purposes depending on whether you need a single match or all matches. The table below highlights the key differences to help you choose the right function for your task.
Feature | re.search() | re.findall() |
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Return Type | Returns a Match object or None | Returns a list of matching strings or tuples |
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Match Count | Returns only the first match | Returns all non-overlapping matches |
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Use Case | Best for checking if a pattern exists | Best for extracting multiple matches |
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Access Groups | Allows access to individual groups using .group() | Capturing groups are returned as tuples |
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Performance | Stops at first match (faster in some cases) | Scans the entire string |
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