---
language:
  - en
  - zh
  - es
  - ur
license: apache-2.0
task_categories:
  - text-generation
tags:
  - code
  - multilingual
  - legesher
  - transpilation
  - tiny-aya-expedition
  - language-decoded
pretty_name: Language Decoded Data
size_categories:
  - 10K<n<100K
configs:
  - config_name: condition-1-en
    data_files:
      - split: train
        path: data/condition-1-en/train-*.parquet
      - split: validation
        path: data/condition-1-en/validation-*.parquet
  - config_name: condition-2-ur
    data_files:
      - split: train
        path: data/condition-2-ur/train-*.parquet
      - split: validation
        path: data/condition-2-ur/validation-*.parquet
  - config_name: condition-2-zh
    data_files:
      - split: train
        path: data/condition-2-zh/train-*.parquet
      - split: validation
        path: data/condition-2-zh/validation-*.parquet
  - config_name: condition-2-es
    data_files:
      - split: train
        path: data/condition-2-es/train-*.parquet
      - split: validation
        path: data/condition-2-es/validation-*.parquet
dataset_info:
  features:
    - name: code
      dtype: string
    - name: code_en
      dtype: string
    - name: language
      dtype: string
    - name: file_path
      dtype: string
    - name: license
      dtype: string
    - name: token_count
      dtype: int64
---

# Language Decoded | Multilingual Code Dataset

Multilingual Python code datasets for the **Language Decoded** project (part of [Cohere's Tiny Aya Expedition](https://aya.for.ai)), investigating whether code's reasoning benefit for language models is **language-dependent** or **structure-dependent**.

## Research Question

> Does fine-tuning on non-English code (Python with translated keywords) improve multilingual reasoning as much as English code does?

Prior work ([Aryabumi et al., 2024 -- "To Code or Not to Code"](https://arxiv.org/abs/2408.10914)) demonstrated that including English code in pre-training data improves downstream reasoning performance by approximately 8%. However, that study only tested English code. This dataset enables the natural follow-up: does the reasoning benefit come from the _structure_ of code, or from the _language_ of its keywords?

## Dataset Description

This dataset provides filtered, quality-controlled Python source code in four configurations: the original English and three keyword-swapped variants (Chinese, Spanish, Urdu). The source data is drawn from [bigcode/the-stack-dedup](https://huggingface.co/datasets/bigcode/the-stack-dedup) (Python subset), filtered for quality using the following criteria:

- AST-valid Python only (must parse without errors)
- Permissive licenses only (MIT, Apache-2.0, BSD, etc.)
- 10--1000 lines of code
- Minimum 21 GitHub stars
- No autogenerated files
- SHA-256 deduplication

Keyword-swapped variants are produced using [Legesher](https://github.com/legesher/legesher) v0.7.3, which translates Python reserved words (37 keywords, 72 builtins, 66 exceptions) into the target language while preserving code structure and semantics.

## Available Configs

| Config           | Condition             | Language | Description                                                                                      |
| ---------------- | --------------------- | -------- | ------------------------------------------------------------------------------------------------ |
| `condition-1-en` | Condition 1 (control) | English  | Unmodified filtered Python from The Stack Dedup                                                  |
| `condition-2-ur` | Condition 2           | Urdu     | Keyword-swapped Python -- 37 keywords, 72 builtins, 66 exceptions translated via Legesher v0.7.3 |
| `condition-2-zh` | Condition 2           | Chinese  | Keyword-swapped Python -- same transpilation method                                              |
| `condition-2-es` | Condition 2           | Spanish  | Keyword-swapped Python -- same transpilation method                                              |

## Schema

| Column        | Type   | Description                                                                                                                                          |
| ------------- | ------ | ---------------------------------------------------------------------------------------------------------------------------------------------------- |
| `code`        | string | Python source code. For condition-2 configs, this is the transpiled (keyword-swapped) version. For condition-1, this is the original English source. |
| `code_en`     | string | Original English Python source code. Identical to `code` for condition-1-en.                                                                         |
| `language`    | string | ISO 639-1 language code: `en`, `ur`, `zh`, or `es`.                                                                                                  |
| `file_path`   | string | Original file path in The Stack Dedup.                                                                                                               |
| `license`     | string | SPDX license identifier for the source file.                                                                                                         |
| `token_count` | int64  | Token count computed using the CohereLabs/tiny-aya-base tokenizer.                                                                                   |

## Experimental Conditions

The Language Decoded experiment uses a ladder of six conditions to isolate the mechanism behind code's reasoning benefit. This dataset currently provides data for conditions 1 and 2:

| Condition       | Name                 | Purpose                                                                    |
| --------------- | -------------------- | -------------------------------------------------------------------------- |
| Baseline        | No fine-tuning       | Establishes the performance floor                                          |
| Condition 1     | English code         | Tests whether code fine-tuning helps at all (replicates Aryabumi et al.)   |
| Condition 2     | Keyword-swapped code | Tests whether the _language_ of keywords matters for the reasoning benefit |
| Conditions 3--6 | (planned)            | Additional controls not yet included in this dataset                       |

## Usage

```python
from datasets import load_dataset

# Load English code (control)
ds = load_dataset("legesher/language-decoded-data", "condition-1-en")

# Load a keyword-swapped variant
ds = load_dataset("legesher/language-decoded-data", "condition-2-ur")
ds = load_dataset("legesher/language-decoded-data", "condition-2-zh")
ds = load_dataset("legesher/language-decoded-data", "condition-2-es")

# Access splits
train = ds["train"]
val = ds["validation"]
```

## Technical Details

| Parameter              | Value                                                                                                              |
| ---------------------- | ------------------------------------------------------------------------------------------------------------------ |
| Source dataset         | [bigcode/the-stack-dedup](https://huggingface.co/datasets/bigcode/the-stack-dedup) (Python subset)                 |
| Transpilation tool     | [Legesher](https://github.com/legesher/legesher) v0.7.3 (legesher-core, legesher-i18n)                             |
| Tokenizer              | CohereLabs/tiny-aya-base                                                                                           |
| Base model             | [CohereLabs/tiny-aya-base](https://huggingface.co/CohereLabs/tiny-aya-base) (3.35B params)                         |
| Train/validation split | 90% / 10% (seed 42)                                                                                                |
| File format            | Parquet (snappy compression)                                                                                       |
| Filtering criteria     | AST-valid, permissive licenses, 10--1000 lines, min 21 GitHub stars, no autogenerated files, SHA-256 deduplication |

## Citation

```bibtex
@misc{language-decoded-2026,
  title={Language Decoded: Investigating Language-Dependent vs. Structure-Dependent Reasoning Benefits of Code},
  author={Madison Edgar and Saad Bazaz and Rafay Mustafa and Sarah Jawaid and Rashik Shahjahan and Khojasteh Mirza and Sohaib Bazaz},
  year={2026},
  publisher={Hugging Face},
  url={https://huggingface.co/datasets/legesher/language-decoded-data}
}
```

## Links

- [Legesher on GitHub](https://github.com/legesher/legesher)
- [Tiny Aya Expedition](https://aya.for.ai)
- [bigcode/the-stack-dedup](https://huggingface.co/datasets/bigcode/the-stack-dedup)

## License

Apache 2.0