exceptions with empty test / val ds config sections

[bmwshop]

What does this PR do ?

Resolves exceptions when trying to train with empty test/ val ds config sections

Collection: ASR

Changelog

In nemo/utils/model_utils.py check if ds_values has values in it before trying to assign names to entries within. These names would have become visible in the test / validation sections of experiment manager (e.g. wandb) - but if these sections are emptty, there is no need to try.

Usage

• You can potentially add a usage example below

# should no longer fail:
python asr_transducer/speech_to_text_rnnt_bpe.py --config-path=../conf/contextnet_rnnt/ --config-name=config_rnnt_bpe.yaml model.tokenizer.dir=data/tokenizer/tokenizer_bpe_v1024/ model.tokenizer.type="bpe" model.train_ds.manifest_filepath=data/LibriSpeech/train_clean_100.json model.train_ds.batch_size=32 model.joint.fuse_loss_wer=true model.joint.fused_batch_size=8 model.decoding.greedy.max_symbols=5 ~model.validation_ds +accelerator="gpu" +strategy="ddp" +devices=4 trainer.max_epochs=1 exp_manager.checkpoint_callback_params.monitor="train_loss" "

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Additional Information

• Related to bug 4067510

[titu1994]

Oh boy, thanks for fixing this