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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 _fetch_pdb(pdb_code):
 """Load PDB file from rcsb.org."""

        txt = None
        url = 'http://www.rcsb.org/pdb/files/%s.pdb' % pdb_code.lower()
        try:
            response = urlopen(url)
            txt = response.read()
            if sys.version_info[0] >= 3:
                txt = txt.decode('utf-8')
            else:
                txt = txt.encode('ascii')
        except HTTPError as e:
            print('HTTP Error %s' % e.code)
        except URLError as e:
            print('URL Error %s' % e.args)
        return url, txt