re.search() in Python

re.search() function in Python is used to search for the first occurrence of a regular expression pattern within a string. It scans the entire string and returns a Match object if a match is found; otherwise, it returns None.

Syntax

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

Parameters:

pattern: Regular expression pattern to search for.
string: String in which the pattern is searched.
flags: Modifiers that control matching behavior, such as case-insensitive matching. The default value is 0.

Return Value:

Match object: Returned when the pattern is found. It provides methods to access the matched text and its position.
None: Returned when no match is found.

Example 1: Using re.search() to Find a Word.

Python

import re

s = "Python is a popular programming language"

res = re.search(r"popular", s)

if res:
    print("Pattern found")
else:
    print("Pattern not found")

Output

Pattern found

Explanation:

re module is imported to perform regular expression matching.
Popular pattern is searched throughout the string.
Since the word exists, re.search() returns a Match object and the condition prints Pattern found.

Example 2: Finding Next Number in a String

Python

import re

s = "I have 25 books and 10 notebooks"

res = re.search(r"\d+", s)

if res:
    print(res.group())
    print(res.start())
    print(res.end())
else:
    print("No number found")

Output

25
7
9

Explanation:

\d+ pattern matches one or more consecutive digits.
group() method returns the matched number, while start() and end() provide its starting and ending indices.
Search stops at the first matching sequence, which is 25.

Example 3: Using re.search() with Flags

Python

import re

s = "Python is an EASY language"

res = re.search(r"easy", s, re.IGNORECASE)

if res:
    print(res.group())
else:
    print("Pattern not found")

Output

EASY

Explanation:

Pattern easy is searched in the given string.
re.IGNORECASE flag enables matching regardless of uppercase or lowercase letters.
group() method returns the actual matched text, preserving its original capitalization.

Syntax

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