python-regexHow to perform a zero length match with Python Regex?

Zero length matches are matches that do not consume any characters. They can be used to find the position of a pattern in a string. In Python, this can be done using the re.search() function with the \b metacharacter.

import re

string = "Hello World"

match = re.search(r"\b", string)

if match:
    print("Match found at position:", match.start())

Output example

Match found at position: 0

The code above uses the re.search() function to search for a zero length match in the string "Hello World". The \b metacharacter is used to indicate a zero length match. If a match is found, the match.start() method is used to print the position of the match.

Code explanation

• import re: imports the re module which contains the re.search() function
• string = "Hello World": creates a string to search for a zero length match
• match = re.search(r"\b", string): uses the re.search() function to search for a zero length match indicated by the \b metacharacter
• if match:: checks if a match was found
• print("Match found at position:", match.start()): prints the position of the match if one was found

Helpful links

• Python Regular Expressions
• Zero Length Matches

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