I am experiencing and issue with the following regex when using finditer. 

    (?=<(?P<tag>\w+)/?>(?:(?P<text>.+?)</(?P=tag)>)?)", "<test><foo2/></test>

(I know it's not the best method of dealing with HTML, and this is a simplified version)

For example:

    [m.groupdict() for m in re.finditer(r"(?=<(?P<tag>\w+)/?>(?:(?P<text>.+?)</(?P=tag)>)?)", "<test><foo2/></test>")]

In Python 2.7, 3.5, and 3.6 it returns

    [{'tag': 'test', 'text': '<foo2/>'}, {'tag': 'foo2', 'text': None}]

But starting with 3.7 it returns

    [{'tag': 'test', 'text': '<foo2/>'}, {'tag': 'foo2', 'text': '<foo2/>'}]

The "text" group appears to be a copy of the previous "text" group.


Some other examples:

    "<test>Hello</test><foo/>" => [{'tag': 'test', 'text': 'Hello'}, {'tag': 'foo', 'text': 'Hello'}] (expected: [{'tag': 'test', 'text': 'Hello'}, {'tag': 'foo', 'text': None}])
    "<test>Hello</test><foo/><foo/>" => [{'tag': 'test', 'text': 'Hello'}, {'tag': 'foo', 'text': 'Hello'}, {'tag': 'foo', 'text': None}] (expected: [{'tag': 'test', 'text': 'Hello'}, {'tag': 'foo', 'text': None}, {'tag': 'foo', 'text': None}])