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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 from_file(self, fname, comment_lead=['c'], compressed_with='use_ext'):
 """ Read a CNF formula from a file in the DIMACS format. A file name is expected as an argument. A default argument is ``comment_lead`` for parsing comment lines. A given file can be compressed by either gzip, bzip2, or lzma. :param fname: name of a file to parse. :param comment_lead: a list of characters leading comment lines :param compressed_with: file compression algorithm :type fname: str :type comment_lead: list(str) :type compressed_with: str Note that the ``compressed_with`` parameter can be ``None`` (i.e. the file is uncompressed), ``'gzip'``, ``'bzip2'``, ``'lzma'``, or ``'use_ext'``. The latter value indicates that compression type should be automatically determined based on the file extension. Using ``'lzma'`` in Python 2 requires the ``backports.lzma`` package to be additionally installed. Usage example: .. code-block:: python """


        with FileObject(fname, mode='r', compression=compressed_with) as fobj:
            self.from_fp(fobj.fp, comment_lead)