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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _open_file_obj(f, mode="r"):
 """ A context manager that provides access to a file. :param f: the file to be opened :type f: a file-like object or path to file :param mode: how to open the file :type mode: string """

    if isinstance(f, six.string_types):
        if f.startswith(("http://", "https://")):
            file_obj = _urlopen(f)
            yield file_obj
            file_obj.close()
        else:
            with open(f, mode) as file_obj:
                yield file_obj
    else:
        yield f