name_a ext_a = ospathsplitextfile_a name_b ext_b = ospathsplitextfile_b

These lines of code use the os module to split the file names and extensions of two files, file_a and file_b.

The os.path.splitext() method splits the file name and extension of a file path. It returns a tuple containing the file name and extension separately.

In this case, the file names and extensions are being stored in variables name_a, ext_a, name_b, and ext_b.

For example, if file_a was "document.pdf", then name_a would be "document" and ext_a would be ".pdf".