Add num_proc parameter to push_to_hub
Hi @SwayStar123 

I'd be interested in taking this up. I plan to add a `num_proc` parameter to `push_to_hub()` and use parallel uploads for shards using `concurrent.futures`. Will explore whether `ThreadPoolExecutor` or `ProcessPoolExecutor` is more suitable based on current implementation. Let me know if that sounds good!
 Just a quick update — `push_to_hub()` already had the `num_proc` argument in its signature and was correctly passing it internally to `_push_parquet_shards_to_hub()`.

The actual change required was inside `_push_parquet_shards_to_hub()` to enable parallel shard uploads using `multiprocessing` when `num_proc > 1`.

@lhoestq @SwayStar123  > Hi @SwayStar123 
> 
> I'd be interested in taking this up. I plan to add a `num_proc` parameter to `push_to_hub()` and use parallel uploads for shards using `concurrent.futures`. Will explore whether `ThreadPoolExecutor` or `ProcessPoolExecutor` is more suitable based on current implementation. Let me know if that sounds good!
> 

Hey thanks for working on it. But I'm not a hf dev so I don't know the best way to do it. done in https://github.com/huggingface/datasets/pull/7606
### Feature request

A number of processes parameter to the dataset.push_to_hub method

### Motivation

Shards are currently uploaded serially which makes it slow for many shards, uploading can be done in parallel and much faster
