Datasets:
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-*
- split: validation
path: data/condition-1-en/validation-*
- config_name: condition-1-en-5k
data_files:
- split: train
path: data/condition-1-en-5k/train-*
- split: validation
path: data/condition-1-en-5k/validation-*
- 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
- config_name: condition-2-es-5k
data_files:
- split: train
path: data/condition-2-es-5k/train-*
- split: validation
path: data/condition-2-es-5k/validation-*
- 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-ur-5k
data_files:
- split: train
path: data/condition-2-ur-5k/train-*
- split: validation
path: data/condition-2-ur-5k/validation-*
- config_name: condition-2-zh
data_files:
- split: train
path: data/condition-2-zh/train-*
- split: validation
path: data/condition-2-zh/validation-*
- config_name: condition-2-zh-5k
data_files:
- split: train
path: data/condition-2-zh-5k/train-*
- split: validation
path: data/condition-2-zh-5k/validation-*
- config_name: condition-3-zh-5k
data_files:
- split: train
path: data/condition-3-zh-5k/train-*
- split: validation
path: data/condition-3-zh-5k/validation-*
dataset_info:
- config_name: condition-1-en
features:
- name: file_path
dtype: string
- name: code
dtype: string
- name: code_en
dtype: string
- name: language
dtype: string
- name: license
dtype: string
- name: token_count
dtype: int32
splits:
- name: train
num_bytes: 403718262
num_examples: 31818
- name: validation
num_bytes: 42626910
num_examples: 3536
download_size: 164619518
dataset_size: 446345172
- config_name: condition-1-en-5k
features:
- name: file_path
dtype: string
- name: code
dtype: string
- name: code_en
dtype: string
- name: language
dtype: string
- name: license
dtype: string
- name: token_count
dtype: int32
splits:
- name: train
num_bytes: 55261555
num_examples: 4500
- name: validation
num_bytes: 6365959
num_examples: 500
download_size: 22897728
dataset_size: 61627514
- config_name: condition-2-es-5k
features:
- name: file_path
dtype: string
- name: code
dtype: string
- name: code_en
dtype: string
- name: language
dtype: string
- name: license
dtype: string
- name: token_count
dtype: int32
splits:
- name: train
num_bytes: 55864731
num_examples: 4500
- name: validation
num_bytes: 6432095
num_examples: 500
download_size: 23031674
dataset_size: 62296826
- config_name: condition-2-ur-5k
features:
- name: file_path
dtype: string
- name: code
dtype: string
- name: code_en
dtype: string
- name: language
dtype: string
- name: license
dtype: string
- name: token_count
dtype: int32
splits:
- name: train
num_bytes: 56906247
num_examples: 4500
- name: validation
num_bytes: 6545730
num_examples: 500
download_size: 23158039
dataset_size: 63451977
- config_name: condition-2-zh
features:
- name: file_path
dtype: string
- name: code
dtype: string
- name: code_en
dtype: string
- name: language
dtype: string
- name: license
dtype: string
- name: token_count
dtype: int32
splits:
- name: train
num_bytes: 405515831
num_examples: 31818
- name: validation
num_bytes: 45065811
num_examples: 3536
download_size: 165387142
dataset_size: 450581642
- config_name: condition-2-zh-5k
features:
- name: file_path
dtype: string
- name: code
dtype: string
- name: code_en
dtype: string
- name: language
dtype: string
- name: license
dtype: string
- name: token_count
dtype: int32
splits:
- name: train
num_bytes: 55793642
num_examples: 4500
- name: validation
num_bytes: 6422792
num_examples: 500
download_size: 22978834
dataset_size: 62216434
- config_name: condition-3-zh-5k
features:
- name: file_path
dtype: large_string
- name: code
dtype: large_string
- name: code_en
dtype: string
- name: language
dtype: large_string
- name: license
dtype: large_string
- name: token_count
dtype: int64
- name: source_type
dtype: large_string
splits:
- name: train
num_bytes: 40782466
num_examples: 4500
- name: validation
num_bytes: 4531385
num_examples: 500
download_size: 17299185
dataset_size: 45313851
- config_name: default
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), 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") 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 (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 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 |
condition-3-zh-5k |
Condition 3 | Chinese | Blended: 3,486 native Chinese code + 1,514 transpiled Python (see Condition 3 section below) |
Schema
Conditions 1--2
| 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. |
Condition 3
Condition 3 blends native Chinese code with transpiled code and adds a source_type column to distinguish them. code_en is populated for transpiled rows (keeping them in sync with conditions 1--2) but null for native code rows, which have no English equivalent.
| Column | Type | Description |
|---|---|---|
file_path |
string | File identifier (native filename or transpiled file path) |
code |
string | The code content (native or transpiled) |
code_en |
string/null | English original -- populated for transpiled rows, null for native code rows |
language |
string | ISO 639-1 language code (zh) |
license |
string | Source license (SPDX identifier, UNKNOWN, or varies) |
token_count |
int64 | Token count computed using the CohereLabs/tiny-aya-base tokenizer |
source_type |
string | "native" (natively Chinese-authored) or "transpiled" (keyword-swapped English) |
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 |
| Condition 3 | Mixed native sources | Tests whether diverse native-language code adds value beyond keyword swapping |
| Conditions 4--6 | (planned) | Additional controls not yet included in this dataset |
Usage
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")
# Load blended native + transpiled (condition 3)
ds = load_dataset("legesher/language-decoded-data", "condition-3-zh-5k")
# Access splits
train = ds["train"]
val = ds["validation"]
# Filter condition-3 by source type
native_only = train.filter(lambda x: x["source_type"] == "native")
Technical Details
| Parameter | Value |
|---|---|
| Source dataset | bigcode/the-stack-dedup (Python subset) |
| Transpilation tool | Legesher v0.7.3 (legesher-core, legesher-i18n) |
| Tokenizer | CohereLabs/tiny-aya-base |
| Base model | 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
@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
License
Apache 2.0