# NameError: name 'LRScheduler' is not defined

**URL:** <https://discuss.huggingface.co/t/nameerror-name-lrscheduler-is-not-defined/134180>\
**Category:** Beginners\
**Created:** [January 4, 2025, 12:50am UTC](https://discuss.huggingface.co/t/nameerror-name-lrscheduler-is-not-defined/134180 "2025-01-04T00:50:50Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![zh-zhang1984](https://sea2.discourse-cdn.com/hellohellohello/user_avatar/discuss.huggingface.co/zh-zhang1984/32/38582_2.png) [@zh-zhang1984](https://discuss.huggingface.co/u/zh-zhang1984)\
**Post date:** [January 4, 2025, 12:50am UTC](https://discuss.huggingface.co/t/nameerror-name-lrscheduler-is-not-defined/134180/1 "2025-01-04T00:50:50Z")

</div>

I have the following code and it reports error:

```auto
from transformers.utils import (
    is_sagemaker_mp_enabled,
    is_torch_available,
    is_torch_xla_available,
    is_training_run_on_sagemaker,
    logging,
)
if is_torch_available():
    from .pytorch_utils import is_torch_greater_or_equal_than_2_0

    if is_torch_greater_or_equal_than_2_0:
        from torch.optim.lr_scheduler import LRScheduler
    else:
        from torch.optim.lr_scheduler import _LRScheduler as LRScheduler
from transformers.trainer_pt_utils import (
    DistributedLengthGroupedSampler,
    DistributedSamplerWithLoop,
    LengthGroupedSampler,
)

{
	"name": "NameError",
	"message": "name 'LRScheduler' is not defined",
	"stack": "---------------------------------------------------------------------------
NameError Traceback (most recent call last)
Cell In[16], line 15
     13 else:
     14 from torch.optim.lr_scheduler import _LRScheduler as LRScheduler
---> 15 from transformers.trainer_pt_utils import (
     16 DistributedLengthGroupedSampler,
     17 DistributedSamplerWithLoop,
     18 LengthGroupedSampler,
     19 )

File /opt/miniconda3/envs/geneformer/lib/python3.10/site-packages/transformers/trainer_pt_utils.py:1368
   1364 def step(self, closure=None) -> Optional[float]:
   1365 pass
-> 1368 class LayerWiseDummyScheduler(LRScheduler):
   1369 \"\"\"
   1370 For Layer-wise optimizers such as GaLoRE optimizer, the optimization and scheduling step
   1371 are already done through the post gradient hooks. Therefore
   1372 the trick is to create a dummy scheduler that can take arbitrary
   1373 args and kwargs and return a no-op during training.
   1374 \"\"\"
   1376 def __init__ (self, *args, **kwargs):

NameError: name 'LRScheduler' is not defined"
}

```

---

<div class="post-metadata">

**Author:** ![John6666](https://sea2.discourse-cdn.com/hellohellohello/user_avatar/discuss.huggingface.co/john6666/32/27664_2.png) [@John6666](https://discuss.huggingface.co/u/John6666)\
**Post date:** [January 4, 2025, 2:14am UTC](https://discuss.huggingface.co/t/nameerror-name-lrscheduler-is-not-defined/134180/2 "2025-01-04T02:14:27Z")

</div>

> from .pytorch\_utils import is\_torch\_greater\_or\_equal\_than\_2\_0

I tried commenting out this block and running it because **pytorch\_utils.py** was missing, but no error occurred.  
Even if I add **from torch.optim.lr\_scheduler import LRScheduler** , it works normally. I think something is probably happening **in pytorch\_utils.py** …