# Differences with torch.distributed.get_rank

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## torch.distributed.get_rank

```python
torch.distributed.get_rank(group=None)
```

For more information, see [torch.distributed.get_rank](https://pytorch.org/docs/1.8.1/distributed.html#torch.distributed.get_rank).

## mindspore.communication.get_rank

```python
mindspore.communication.get_rank(group=GlobalComm.WORLD_COMM_GROUP)
```

For more information, see [mindspore.communication.get_rank](https://mindspore.cn/docs/en/r2.3.0rc1/api_python/mindspore.communication.html#mindspore.communication.get_rank).

## Differences

PyTorch: The input of this interface is the communication group `group`.
The output is the `rank` of the process that calls this interface, and returns -1 if the process is not in `group`.

MindSpore: The input of this interface is the communication group `group`. The output is the `rank` of the process that calls this interface. Since `get_rank` should be called after `init`, the process that calls this interface should be in `group`. If `get_rank` is called before `init`, it will raise error.

| Class | Sub-class |PyTorch | MindSpore | Difference |
| --- | --- | --- | --- |---|
| Parameter  | Parameter 1 | group | group |No difference|