ImportError: cannot import name 'QuantStub' from 'torch.ao.quantization'

Question

ImportError: cannot import name 'QuantStub' from 'torch.ao.quantization'. I am calling functions from histocartography python package

/vol/ideadata/oc69ubiw/conda/pathoexplainer/lib/python3.10/site-packages/torchvision/io/image.py:13: UserWarning: Failed to load image Python extension: /vol/ideadata/oc69ubiw/conda/pathoexplainer/lib/python3.10/site-packages/torchvision/image.so: undefined symbol: _ZN3c106detail19maybe_wrap_dim_slowEllb
warn(f"Failed to load image Python extension: {e}")
Traceback (most recent call last):
 File "/vol/ideadata/oc69ubiw/Explainer_GNN/patho-quant-explainer/core/generate_cell_graphs.py", line 14, in <module>
from histocartography.preprocessing import (
 File "/vol/ideadata/oc69ubiw/conda/pathoexplainer/lib/python3.10/site-packages/histocartography/preprocessing/__init__.py", line 2, in <module>
from .feature_extraction import HandcraftedFeatureExtractor
 File "/vol/ideadata/oc69ubiw/conda/pathoexplainer/lib/python3.10/site-packages/histocartography/preprocessing/feature_extraction.py", line 13, in <module>
import torchvision
 File "/vol/ideadata/oc69ubiw/conda/pathoexplainer/lib/python3.10/site-packages/torchvision/__init__.py", line 7, in <module>
from torchvision import models
 File "/vol/ideadata/oc69ubiw/conda/pathoexplainer/lib/python3.10/site-packages/torchvision/models/__init__.py", line 18, in <module>
from . import quantization
 File "/vol/ideadata/oc69ubiw/conda/pathoexplainer/lib/python3.10/site-packages/torchvision/models/quantization/__init__.py", line 3, in <module>
from .mobilenet import *
 File "/vol/ideadata/oc69ubiw/conda/pathoexplainer/lib/python3.10/site-packages/torchvision/models/quantization/mobilenet.py", line 1, in <module>
from .mobilenetv2 import *  # noqa: F401, F403
 File "/vol/ideadata/oc69ubiw/conda/pathoexplainer/lib/python3.10/site-packages/torchvision/models/quantization/mobilenetv2.py", line 6, in <module>
from torch.ao.quantization import QuantStub, DeQuantStub
ImportError: cannot import name 'QuantStub' from 'torch.ao.quantization' (/vol/ideadata/oc69ubiw/conda/pathoexplainer/lib/python3.10/site-packages/torch/ao/quantization/__init__.py)

Answer 1

I had the same error. Reinstalling/Updating PyTorch fixed it. Seems to be supported by https://discuss.pytorch.org/t/cannot-import-name-quantstub-from-torch-ao-quantization/158979/2 . Jerry Zhang mentions that "...we are deprecating the torch.quantization namespace, and torch.ao.quantization is the recommended one".