question: How to use predict function to return predictions
context: How to get predictions
    class OurModel(LightningModule):
        def __init__(self):
          super(OurModel,self).__init__()
          self.layer = MyModelV3()
        def forward(self,x):
          return self.layer(x)
  
    def train_dataloader(self):
      return DataLoader(DataReader(train_df))
  
    def training_step(self,batch,batch_idx):
      return loss
  
    def test_dataloader(self):
      return DataLoader(DataReader(test_df))
      
    def test_step(self,batch,batch_idx):
      image,label=batch
      out=self(image)
      loss=self.criterion(out,label)
      return loss
  
    def predict(self, batch):
          return self(batch) 
  I am not sure, how to use predict function. How to define data loader for predict function. I want to get predictions for test_df. But now idea how to do this.
answer: Hi @talhaanwarch, in order to get predictions from a data loader you need to implement predict_step in your LightningModule (docs here: https://pytorch-lightning.readthedocs.io/en/stable/common/lightning_module.html#predict-step). You would then be able to call Trainer.predict with the dataloader you want use following the API here: https://pytorch-lightning.readthedocs.io/en/stable/api/pytorch_lightning.trainer.trainer.html#pytorch_lightning.trainer.trainer.Trainer.predict
  Hope that helps 😃