Add docstring for tokenizer usage in data preprocessing script
State: closed | Pull request: yes
Labels: name: Run CICD

# What does this PR do ?

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**Collection**: [Note which collection this PR will affect]

# Changelog 
- Add specific line by line info of high level changes in this PR.

# Usage
* You can potentially add a usage example below

```python
# Add a code snippet demonstrating how to use this 
```

# GitHub Actions CI

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# Before your PR is "Ready for review"
**Pre checks**:
- [ ] Make sure you read and followed [Contributor guidelines](https://github.com/NVIDIA/NeMo/blob/main/CONTRIBUTING.md)
- [ ] Did you write any new necessary tests?
- [ ] Did you add or update any necessary documentation?
- [ ] Does the PR affect components that are optional to install? (Ex: Numba, Pynini, Apex etc)
  - [ ] Reviewer: Does the PR have correct import guards for all optional libraries?
  
**PR Type**:
- [ ] New Feature
- [ ] Bugfix
- [ ] Documentation

If you haven't finished some of the above items you can still open "Draft" PR.


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# Additional Information
* Related to # (issue)


<!-- pylint-output-strict-mode-false -->

beep boop 🤖: 🙏 The following files have warnings. In case you are familiar with these, please try helping us to improve the code base.

---

Your code was analyzed with PyLint. The following annotations have been identified:

```
************* Module preprocess_data_for_megatron
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:216:0: C0301: Line too long (168/119) (line-too-long)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:266:0: C0301: Line too long (164/119) (line-too-long)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:117:0: C0115: Missing class docstring (missing-class-docstring)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:130:0: C0115: Missing class docstring (missing-class-docstring)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:131:4: C0116: Missing function or method docstring (missing-function-docstring)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:135:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:152:0: C0115: Missing class docstring (missing-class-docstring)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:156:4: C0116: Missing function or method docstring (missing-function-docstring)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:176:4: C0116: Missing function or method docstring (missing-function-docstring)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:209:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:286:0: C0116: Missing function or method docstring (missing-function-docstring)

-----------------------------------
Your code has been rated at 9.36/10
```

---

Mitigation guide:

* Add sensible and useful docstrings to functions and methods
* For trivial methods like getter/setters, consider adding `# pylint: disable=C0116` inside the function itself
* To disable multiple functions/methods at once, put a `# pylint: disable=C0116` before the first and a `# pylint: enable=C0116` after the last.

By applying these rules, we reduce the occurance of this message in future.

Thank you for improving NeMo's documentation!

<!-- pylint-output-strict-mode-false -->

beep boop 🤖: 🙏 The following files have warnings. In case you are familiar with these, please try helping us to improve the code base.

---

Your code was analyzed with PyLint. The following annotations have been identified:

```
************* Module preprocess_data_for_megatron
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:216:0: C0301: Line too long (168/119) (line-too-long)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:266:0: C0301: Line too long (164/119) (line-too-long)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:117:0: C0115: Missing class docstring (missing-class-docstring)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:130:0: C0115: Missing class docstring (missing-class-docstring)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:131:4: C0116: Missing function or method docstring (missing-function-docstring)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:135:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:152:0: C0115: Missing class docstring (missing-class-docstring)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:156:4: C0116: Missing function or method docstring (missing-function-docstring)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:176:4: C0116: Missing function or method docstring (missing-function-docstring)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:209:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/nlp_language_modeling/preprocess_data_for_megatron.py:286:0: C0116: Missing function or method docstring (missing-function-docstring)

-----------------------------------
Your code has been rated at 9.36/10
```

---

Mitigation guide:

* Add sensible and useful docstrings to functions and methods
* For trivial methods like getter/setters, consider adding `# pylint: disable=C0116` inside the function itself
* To disable multiple functions/methods at once, put a `# pylint: disable=C0116` before the first and a `# pylint: enable=C0116` after the last.

By applying these rules, we reduce the occurance of this message in future.

Thank you for improving NeMo's documentation!

[🤖]: Hi @suiyoubi 👋,

We wanted to let you know that a [CICD pipeline](https://github.com/NVIDIA/NeMo/actions/runs/12433348300) for this PR just finished successfully

So it might be time to merge this PR or get some approvals

I'm just a bot so I'll leave it you what to do next.

//cc @pablo-garay @ko3n1g