Requirements should specify pyarrow<1
Hello @mathcass I would want to work on this issue. May I do the same?  @punitaojha, certainly. Feel free to work on this. Let me know if you need any help or clarity. Hello @mathcass 
1. I did fork the repository and clone the same on my local system. 

2. Then learnt about how we can publish our package on pypi.org. Also, found some instructions on same in setup.py documentation.

3. Then I Perplexity document link that you shared above. I created a colab link from there keep both tensorflow and pytorch means a mixed option and tried to run it in colab but I encountered no errors at a point where you mentioned. Can you help me to figure out the issue. 

4.Here is the link of the colab file with my saved responses. 
https://colab.research.google.com/drive/1hfYz8Ira39FnREbxgwa_goZWpOojp2NH?usp=sharing Also, please share some links which made you conclude that pyarrow < 1 would help.  Access granted for the colab link.  Thanks for looking at this @punitaojha and thanks for sharing the notebook. 

I just tried to reproduce this on my own (based on the environment where I had this issue) and I can't reproduce it somehow. If I run into this again, I'll include some steps to reproduce it. I'll close this as invalid. 

Thanks again.  I am sorry for hijacking this closed issue, but I believe I was able to reproduce this very issue. Strangely enough, it also turned out that running `pip install "pyarrow<1" --upgrade` did indeed fix the issue (PyArrow was installed in version `0.14.1` in my case).

Please see the Colab below:

https://colab.research.google.com/drive/15QQS3xWjlKW2aK0J74eEcRFuhXUddUST

Thanks!
I was looking at the docs on [Perplexity](https://huggingface.co/transformers/perplexity.html) via GPT2. When you load datasets and try to load Wikitext, you get the error,

```
module 'pyarrow' has no attribute 'PyExtensionType'
```
I traced it back to datasets having installed PyArrow 1.0.1 but there's not pinning in the setup file. 

https://github.com/huggingface/datasets/blob/e86a2a8f869b91654e782c9133d810bb82783200/setup.py#L68

Downgrading by installing `pip install "pyarrow<1"` resolved the issue.