Anatoly Myachev

> I think what we should do is to make a more describable error message in these situations, something like: "you're trying to pass pandas object to a modin's method,...

> When merging into master? Potentially yes, but we need to check how long they take. It may take too long for each push.

@zmbc I think it's quite similar to what `from_partitions` function does. https://github.com/modin-project/modin/blob/29d9da056a4e4766314c4ae9ea62b33e0d52e662/modin/distributed/dataframe/pandas/partitions.py#L129-L136 Example: ```python import pandas as pd from modin.distributed.dataframe.pandas import from_partitions import ray ray.init(num_cpus=4) partitions = list(map(lambda number: ray.put(pd.DataFrame([number])),...

> Thanks! That's helpful, but it does require me to interact directly with the underlying engine (Ray in your example). That's kind of a pain when I want to write...

https://github.com/modin-project/modin/issues/7234

Hi @DimitarSirakov, thanks for the contribution! I can reproduce the problem. Take a look.

@DimitarSirakov iteration over the index occurs when converting; if the index is not unique, then it may return not a scalar, but a Modin Series, with which `pyarrow` cannot work....

@DimitarSirakov if this option is not suitable for you, then we may consider implementing [`def __arrow_array__(self, type=None):`](https://arrow.apache.org/docs/python/extending_types.html#extending-pyarrow) for Series object, which will fix the problems with your current reproducer, but...

> So far it looks like problem is in Omnisci side, they are looking into it Any updates here?

> The Fold operator has no such note, but when I try to run an example that changes the shape, it doesn't work: Hi @zmbc! Good observation. This doesn't work...