From a16a0e94f534e26c554bfb5ced63dde773de135f Mon Sep 17 00:00:00 2001
From: x54-729 <17307130121@fudan.edu.cn>
Date: Wed, 1 Jun 2022 16:19:00 +0000
Subject: [PATCH] =?UTF-8?q?driver=20=E5=9C=A8=20dataloader=20=E4=B8=BA?=
 =?UTF-8?q?=E7=A9=BA=E6=97=B6=E8=BF=9B=E8=A1=8C=E8=AD=A6=E5=91=8A?=
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---
 fastNLP/core/drivers/jittor_driver/jittor_driver.py | 3 +++
 fastNLP/core/drivers/paddle_driver/paddle_driver.py | 3 +++
 fastNLP/core/drivers/torch_driver/torch_driver.py   | 3 +++
 3 files changed, 9 insertions(+)

diff --git a/fastNLP/core/drivers/jittor_driver/jittor_driver.py b/fastNLP/core/drivers/jittor_driver/jittor_driver.py
index e486df8e..63ac6ec4 100644
--- a/fastNLP/core/drivers/jittor_driver/jittor_driver.py
+++ b/fastNLP/core/drivers/jittor_driver/jittor_driver.py
@@ -71,6 +71,9 @@ class JittorDriver(Driver):
     def check_dataloader_legality(self, dataloader):
         if not isinstance(dataloader, (Dataset, JittorDataLoader)):
             raise TypeError(f"{Dataset} or {JittorDataLoader} is expected, instead of `{type(dataloader)}`")
+        if len(dataloader) == 0:
+            logger.rank_zero_warning("Your dataloader is empty, which is not recommended because it "
+                                        "may cause some unexpected exceptions.", once=True)
 
     @staticmethod
     def _check_optimizer_legality(optimizers):
diff --git a/fastNLP/core/drivers/paddle_driver/paddle_driver.py b/fastNLP/core/drivers/paddle_driver/paddle_driver.py
index f809f9ec..a3fde3af 100644
--- a/fastNLP/core/drivers/paddle_driver/paddle_driver.py
+++ b/fastNLP/core/drivers/paddle_driver/paddle_driver.py
@@ -99,6 +99,9 @@ class PaddleDriver(Driver):
         if dataloader.batch_size is None and dataloader.batch_sampler is None:
             raise ValueError("Please ensure at least one of your dataloader's batch_size and batch_sampler"
                             "is not None")
+        if len(dataloader) == 0:
+            logger.rank_zero_warning("Your dataloader is empty, which is not recommended because it "
+                                        "may cause some unexpected exceptions.", once=True)
 
     @staticmethod
     def _check_optimizer_legality(optimizers):
diff --git a/fastNLP/core/drivers/torch_driver/torch_driver.py b/fastNLP/core/drivers/torch_driver/torch_driver.py
index 9449782b..841e6614 100644
--- a/fastNLP/core/drivers/torch_driver/torch_driver.py
+++ b/fastNLP/core/drivers/torch_driver/torch_driver.py
@@ -94,6 +94,9 @@ class TorchDriver(Driver):
     def check_dataloader_legality(self, dataloader):
         if not isinstance(dataloader, DataLoader):
             raise TypeError(f"{DataLoader} is expected, instead of `{type(dataloader)}`")
+        if len(dataloader) == 0:
+            logger.rank_zero_warning("Your dataloader is empty, which is not recommended because it "
+                                        "may cause some unexpected exceptions.", once=True)
 
     @staticmethod
     def _check_optimizer_legality(optimizers):