Regular Expressions difference between [0-9] and [0-9.]

Question

I just started looking into regular expressions, and was wondering what the difference is between the following:

def test():
    string = "He was 75 in the 1985sdfdhs 45"
    y = re.findall('[0-9]+', string)
    print(y)

test()

and this

def test2():
    string = "He was 75 in the 1985sdfdhs 45"
    y = re.findall('[0-9.]+', string)
    print(y)

test2()

To my understanding the "." matches any character, so I would have thought the output for test2 would equal ['75', '1985sdfdhs', '45'], instead they are both ['75', '1985', '45']. Just trying to figure out whats going on here. Thanks.

Answer 1

When within the brackets [ and ], the dot is considered a character by itself. So the second regex will match 0-9 as well as the decimal dot. The brackets denote a character set and will match one of the characters in the set (which is why the . is considered a character and not a specifier).

EDIT: As an additional note, while you're learning about RegEx, I recommend https://regex101.com/ which will break down each part of the RegEx for you.