+
+class OutputFile(object):
+ """Represents a file returned by one of the converters."""
+
+ _bytes = None
+ _filename = None
+
+ def __del__(self):
+ if self._filename:
+ os.unlink(self._filename)
+
+ def __nonzero__(self):
+ return self._bytes is not None or self._filename is not None
+
+ @classmethod
+ def from_bytes(cls, bytestring):
+ """Converter returns contents of a file as a string."""
+
+ instance = cls()
+ instance._bytes = bytestring
+ return instance
+
+ @classmethod
+ def from_filename(cls, filename):
+ """Converter returns contents of a file as a named file."""
+
+ instance = cls()
+ instance._filename = filename
+ return instance
+
+ def get_bytes(self):
+ """Get file's contents as a bytestring."""
+
+ if self._filename is not None:
+ with open(self._filename, 'rb') as f:
+ return f.read()
+ else:
+ return self._bytes
+
+ def get_file(self):
+ """Get file as a file-like object."""
+
+ if self._bytes is not None:
+ return six.BytesIO(self._bytes)
+ elif self._filename is not None:
+ return open(self._filename, 'rb')
+
+ def get_filename(self):
+ """Get file as a fs path."""
+
+ if self._filename is not None:
+ return self._filename
+ elif self._bytes is not None:
+ temp = NamedTemporaryFile(prefix='librarian-', delete=False)
+ temp.write(self._bytes)
+ temp.close()
+ self._filename = temp.name
+ return self._filename
+ else:
+ return None
+
+ def save_as(self, path):
+ """Save file to a path. Create directories, if necessary."""
+
+ dirname = os.path.dirname(os.path.abspath(path))
+ makedirs(dirname)
+ shutil.copy(self.get_filename(), path)
+
+
+class URLOpener(FancyURLopener):
+ version = 'FNP Librarian (http://github.com/fnp/librarian)'
+urllib._urlopener = URLOpener()