na(&#39;&#39;).astype(str)
        else:
            self.data = pd.read_csv(self.datapath, dtype=str, na_filter=False).fillna(&#39;&#39;).astype(str)

        if self.VERBOSE:
            print(&#39;data reading complete&#39;)
            
        self.data = self.synccols(self.data)
        
        if self.VERBOSE:
            print(self.data)
        
        num_training=np.rint(self.training_fraction*self.data.index.size).astype(int)
        training_index=np.random.choice(self.data.index.values,num_t