The below code worked on Python 3.5, 3.6, 3.7, and 3.8, but it now crashes on Python 3.9.


from contextlib import contextmanager


@contextmanager
def open_files(names):
    yield names  # This would actually return file objects


with open_files(['file1.txt', 'file2.txt']) as (first, *rest):
    print(first, rest)


The error shown is:

    with open_files(['file1.txt', 'file2.txt']) as (first, *rest):
                                                                 ^
SyntaxError: invalid syntax