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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 _init_codebook(self):
 """Internal function to set the codebook or to indicate it to the C++ code that it should be randomly initialized. """

        codebook_size = self._n_columns * self._n_rows * self.n_dim
        if self.codebook is None:
            if self._initialization == "random":
                self.codebook = np.zeros(codebook_size, dtype=np.float32)
                self.codebook[0:2] = [1000, 2000]
            else:
                self._pca_init()
        elif self.codebook.size != codebook_size:
            raise Exception("Invalid size for initial codebook")
        else:
            if self.codebook.dtype != np.float32:
                print("Warning: initialcodebook was not float32. A 32-bit "
                      "copy was made")
                self.codebook = np.float32(self.codebook)
        self.codebook.shape = (codebook_size, )