I followed this colab notebook 2 to install torch_geometric to Google Colab:
(I turned on the GPU of the notebook and ensured the version of torch and Cuda is 1.9.0+cu102)
!pip install -q torch-scatter -f https://pytorch-geometric.com/whl/torch-1.9.0+cu102.html
!pip install -q torch-sparse -f https://pytorch-geometric.com/whl/torch-1.9.0+cu102.html
!pip install -q torch-geometric

And it appeared to be successful:
Looking in links: https://pytorch-geometric.com/whl/torch-1.9.0+cu102.html
Requirement already satisfied: torch-scatter in /usr/local/lib/python3.7/dist-packages (2.0.7)
Looking in links: https://pytorch-geometric.com/whl/torch-1.9.0+cu102.html
Requirement already satisfied: torch-sparse in /usr/local/lib/python3.7/dist-packages (0.6.10)
Requirement already satisfied: scipy in /usr/local/lib/python3.7/dist-packages (from torch-sparse) (1.4.1)
Requirement already satisfied: numpy>=1.13.3 in /usr/local/lib/python3.7/dist-packages (from scipy->torch-sparse) (1.19.5)
Requirement already satisfied: torch-geometric in /usr/local/lib/python3.7/dist-packages (1.7.2)
Requirement already satisfied: pyparsing in /usr/local/lib/python3.7/dist-packages (from torch-geometric) (2.4.7)
Requirement already satisfied: networkx in /usr/local/lib/python3.7/dist-packages (from torch-geometric) (2.5.1)
Requirement already satisfied: pandas in /usr/local/lib/python3.7/dist-packages (from torch-geometric) (1.1.5)
Requirement already satisfied: scipy in /usr/local/lib/python3.7/dist-packages (from torch-geometric) (1.4.1)
Requirement already satisfied: scikit-learn in /usr/local/lib/python3.7/dist-packages (from torch-geometric) (0.22.2.post1)
Requirement already satisfied: tqdm in /usr/local/lib/python3.7/dist-packages (from torch-geometric) (4.41.1)
Requirement already satisfied: requests in /usr/local/lib/python3.7/dist-packages (from torch-geometric) (2.23.0)
Requirement already satisfied: rdflib in /usr/local/lib/python3.7/dist-packages (from torch-geometric) (5.0.0)
Requirement already satisfied: googledrivedownloader in /usr/local/lib/python3.7/dist-packages (from torch-geometric) (0.4)
Requirement already satisfied: python-louvain in /usr/local/lib/python3.7/dist-packages (from torch-geometric) (0.15)
Requirement already satisfied: numpy in /usr/local/lib/python3.7/dist-packages (from torch-geometric) (1.19.5)
Requirement already satisfied: jinja2 in /usr/local/lib/python3.7/dist-packages (from torch-geometric) (2.11.3)
Requirement already satisfied: MarkupSafe>=0.23 in /usr/local/lib/python3.7/dist-packages (from jinja2->torch-geometric) (2.0.1)
Requirement already satisfied: decorator<5,>=4.3 in /usr/local/lib/python3.7/dist-packages (from networkx->torch-geometric) (4.4.2)
Requirement already satisfied: pytz>=2017.2 in /usr/local/lib/python3.7/dist-packages (from pandas->torch-geometric) (2018.9)
Requirement already satisfied: python-dateutil>=2.7.3 in /usr/local/lib/python3.7/dist-packages (from pandas->torch-geometric) (2.8.1)
Requirement already satisfied: six>=1.5 in /usr/local/lib/python3.7/dist-packages (from python-dateutil>=2.7.3->pandas->torch-geometric) (1.15.0)
Requirement already satisfied: isodate in /usr/local/lib/python3.7/dist-packages (from rdflib->torch-geometric) (0.6.0)
Requirement already satisfied: idna<3,>=2.5 in /usr/local/lib/python3.7/dist-packages (from requests->torch-geometric) (2.10)
Requirement already satisfied: certifi>=2017.4.17 in /usr/local/lib/python3.7/dist-packages (from requests->torch-geometric) (2021.5.30)
Requirement already satisfied: chardet<4,>=3.0.2 in /usr/local/lib/python3.7/dist-packages (from requests->torch-geometric) (3.0.4)
Requirement already satisfied: urllib3!=1.25.0,!=1.25.1,<1.26,>=1.21.1 in /usr/local/lib/python3.7/dist-packages (from requests->torch-geometric) (1.24.3)
Requirement already satisfied: joblib>=0.11 in /usr/local/lib/python3.7/dist-packages (from scikit-learn->torch-geometric) (1.0.1)

However, when I import the torch_geometric or its dependency, torch_sparse, I received the error:
OSError: /usr/local/lib/python3.7/dist-packages/torch_sparse/_convert_cuda.so: undefined symbol: _ZNK2at6Tensor6deviceEv

How can I fix it? I believe this unsolved post 26 is facing the same issue.
I guess it might be due to the early installation with the wrong version. If so, how should I delete it and reinstall the corrected one?
Any advice would be highly appreciated.