pythonregexstringsearch

How can I find all matches to a regular expression in Python?


When I use the re.search() function to find matches in a block of text, the program exits once it finds the first match in the block of text.

How do I do this repeatedly where the program doesn't stop until ALL matches have been found? Is there a separate function to do this?


Solution

  • Use re.findall or re.finditer instead.

    re.findall(pattern, string) returns a list of matching strings.

    re.finditer(pattern, string) returns an iterator over MatchObject objects.

    Example:

    re.findall( r'all (.*?) are', 'all cats are smarter than dogs, all dogs are dumber than cats')
    # Output: ['cats', 'dogs']
    
    [x.group() for x in re.finditer( r'all (.*?) are', 'all cats are smarter than dogs, all dogs are dumber than cats')]
    # Output: ['all cats are', 'all dogs are']