unsloth/studio/backend/utils/datasets/format_conversion.py
Roland Tannous 32bbccc573 fix: resolve bare-filename images via HF repo lookup
Datasets like VQAonline store image filenames (e.g. "img.png") without
the directory prefix. Build a basename→repo_path lookup using
list_repo_files, then resolve each file via hf_hub_download.
2026-03-09 23:37:00 +00:00

611 lines
22 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-only - See /studio/LICENSE.AGPL-3.0
# Copyright © 2025 Unsloth AI
"""
Format conversion utilities for dataset processing.
This module contains functions for converting between dataset formats
(Alpaca, ShareGPT, ChatML) and standardizing chat formats.
"""
import os
from datasets import IterableDataset
def standardize_chat_format(
dataset,
tokenizer=None,
aliases_for_system=["system",],
aliases_for_user=["user", "human", "input",],
aliases_for_assistant=["gpt", "assistant", "output",],
batch_size=1000,
num_proc=None,
):
"""
Our own standardization function that handles BOTH messages and conversations.
Converts non-standard role names and keys to standard format.
"""
import collections
import itertools
from datasets import IterableDataset
# Check if vision tokenizer is used
is_vlm = False
if tokenizer is not None:
if hasattr(tokenizer, "image_processor") or hasattr(tokenizer, "tokenizer"):
is_vlm = True
column_names = set(next(iter(dataset)).keys())
# Check for both 'conversations' and 'messages'
chat_column = None
if "conversations" in column_names:
chat_column = "conversations"
elif "messages" in column_names:
chat_column = "messages"
elif "texts" in column_names:
chat_column = "texts"
else:
return dataset # No chat column found
# Inspect structure
examples = itertools.islice(dataset, 10)
uniques = collections.defaultdict(list)
for example in examples:
for message in example[chat_column]:
for key, value in message.items():
if type(value) is not str:
continue # Skip non-string values
uniques[key].append(value)
if len(uniques.keys()) != 2:
return dataset # Unexpected structure
keys = list(uniques.keys())
length_first = len(set(uniques[keys[0]]))
length_second = len(set(uniques[keys[1]]))
# Determine which is role and which is content
if length_first < length_second:
role_key = keys[0]
content_key = keys[1]
else:
role_key = keys[1]
content_key = keys[0]
# Mapping for aliases
aliases_mapping = {}
for x in aliases_for_system: aliases_mapping[x] = "system"
for x in aliases_for_user: aliases_mapping[x] = "user"
for x in aliases_for_assistant: aliases_mapping[x] = "assistant"
def _standardize_dataset(examples):
convos = examples[chat_column]
all_convos = []
for convo in convos:
new_convo = []
for message in convo:
# Get original role and content
original_role = message.get(role_key, "")
original_content = message.get(content_key, "")
# Map to standard role name
standard_role = aliases_mapping.get(original_role, original_role)
# Handle VLM format
if is_vlm:
original_content = [{"type": "text", "text": original_content}]
# Create dict with EXPLICIT ORDER
new_message = {"role": standard_role, "content": original_content}
new_convo.append(new_message)
all_convos.append(new_convo)
return {chat_column: all_convos}
dataset_map_kwargs = {
'batched': True,
'batch_size': batch_size,
}
if not isinstance(dataset, IterableDataset):
from utils.hardware import safe_num_proc
if num_proc is None or type(num_proc) is not int:
num_proc = safe_num_proc()
else:
num_proc = safe_num_proc(num_proc)
dataset_map_kwargs['num_proc'] = num_proc
dataset_map_kwargs['desc'] = "Standardizing chat format"
return dataset.map(_standardize_dataset, **dataset_map_kwargs)
def convert_chatml_to_alpaca(dataset, batch_size=1000, num_proc=None):
"""
Converts ChatML format (messages OR conversations) to Alpaca format.
Handles both standardized and ShareGPT formats.
Supports:
- "messages" or "conversations" column
- "role"/"content" (standard) or "from"/"value" (ShareGPT)
"""
from torch.utils.data import IterableDataset
def _convert(examples):
# Auto-detect which column name is used
chatml_data = examples.get("messages") or examples.get("conversations") or examples.get("texts")
if chatml_data is None:
raise ValueError("No 'messages' or 'conversations' or 'texts' column found.")
instructions = []
outputs = []
inputs = []
for convo in chatml_data:
instruction = ""
output = ""
for msg in convo:
# Handle both standard and ShareGPT formats
role = msg.get("role") or msg.get("from")
content = msg.get("content") or msg.get("value")
# Get first user message as instruction
if role in ["user", "human", "input"] and not instruction:
instruction = content
# Get first assistant message as output
elif role in ["assistant", "gpt", "output"] and not output:
output = content
break # Stop after first assistant response
instructions.append(instruction)
inputs.append("") # Alpaca typically has empty input
outputs.append(output)
return {
"instruction": instructions,
"input": inputs,
"output": outputs
}
dataset_map_kwargs = {
'batched': True,
'batch_size': batch_size,
}
if not isinstance(dataset, IterableDataset):
from utils.hardware import safe_num_proc
if num_proc is None or type(num_proc) is not int:
num_proc = safe_num_proc()
else:
num_proc = safe_num_proc(num_proc)
dataset_map_kwargs['num_proc'] = num_proc
dataset_map_kwargs['desc'] = "Converting ChatML to Alpaca format"
return dataset.map(_convert, **dataset_map_kwargs)
def convert_alpaca_to_chatml(dataset, batch_size=1000, num_proc=None):
"""
Converts Alpaca format to ChatML format.
Output format: Uses 'conversations' column with standard 'role'/'content' structure.
"""
from torch.utils.data import IterableDataset
def _convert(examples):
conversations = []
for i in range(len(examples["instruction"])):
instruction = examples["instruction"][i]
input_text = examples.get("input", [""] * len(examples["instruction"]))[i]
output = examples["output"][i]
# Combine instruction and input (if exists) for user message
if input_text and input_text.strip():
user_content = f"{instruction}\n\n{input_text}".strip()
else:
user_content = instruction
# Build conversation in standard ChatML format
convo = [
{"role": "user", "content": user_content},
{"role": "assistant", "content": output}
]
conversations.append(convo)
return {"conversations": conversations}
dataset_map_kwargs = {
'batched': True,
'batch_size': batch_size,
}
if not isinstance(dataset, IterableDataset):
from utils.hardware import safe_num_proc
if num_proc is None or type(num_proc) is not int:
num_proc = safe_num_proc()
else:
num_proc = safe_num_proc(num_proc)
dataset_map_kwargs['num_proc'] = num_proc
dataset_map_kwargs['desc'] = "Converting Alpaca to ChatML format"
return dataset.map(_convert, **dataset_map_kwargs)
def _format_eta(seconds):
"""Format seconds into a human-readable ETA string."""
if seconds < 60:
return f"{seconds:.0f}s"
elif seconds < 3600:
m, s = divmod(int(seconds), 60)
return f"{m}m {s}s"
else:
h, remainder = divmod(int(seconds), 3600)
m, _ = divmod(remainder, 60)
return f"{h}h {m}m"
def convert_to_vlm_format(
dataset,
instruction=None,
text_column="text",
image_column="image",
dataset_name=None,
progress_callback=None,
):
"""
Converts simple {image, text} format to VLM messages format.
Returns a LIST, not a HuggingFace Dataset (to preserve PIL Images).
For URL-based image datasets, runs a 200-sample parallel probe first to
estimate download speed and failure rate, then reports time estimate or
warning through progress_callback before proceeding with the full conversion.
Args:
progress_callback: Optional callable(status_message=str) to report
progress to the training overlay.
Returns:
list: List of dicts with 'messages' field
"""
from PIL import Image
from .vlm_processing import generate_smart_vlm_instruction
def _notify(msg):
"""Send status update to the training overlay if callback is available."""
if progress_callback:
progress_callback(status_message=msg)
# Generate smart instruction if not provided
if instruction is None:
instruction_info = generate_smart_vlm_instruction(
dataset,
text_column=text_column,
image_column=image_column,
dataset_name=dataset_name,
)
instruction = instruction_info["instruction"]
instruction_column = instruction_info.get("instruction_column")
uses_dynamic = instruction_info["uses_dynamic_instruction"]
print(f"📝 Auto-detected instruction type: {instruction_info['instruction_type']}")
print(f"📝 Confidence: {instruction_info['confidence']:.2f}")
if not uses_dynamic:
print(f"📝 Using instruction: '{instruction}'")
else:
print(f"📝 Using dynamic instructions from column: '{instruction_column}'")
else:
instruction_column = None
uses_dynamic = False
def _convert_single_sample(sample):
"""Convert a single sample to VLM format."""
# Get image (might be PIL Image, local path, URL, or bare filename)
image_data = sample[image_column]
if isinstance(image_data, str):
if image_data.startswith(("http://", "https://")):
import fsspec
from io import BytesIO
with fsspec.open(image_data, "rb", expand=True) as f:
image_data = Image.open(BytesIO(f.read())).convert("RGB")
elif _image_lookup is not None and image_data in _image_lookup:
# Bare filename → resolve via HF repo lookup
from huggingface_hub import hf_hub_download
local_path = hf_hub_download(
dataset_name, _image_lookup[image_data], repo_type="dataset",
)
image_data = Image.open(local_path).convert("RGB")
else:
image_data = Image.open(image_data).convert("RGB")
# Get text
text_data = sample[text_column]
# Get instruction (static or dynamic)
if uses_dynamic and instruction_column:
current_instruction = sample[instruction_column]
else:
current_instruction = instruction
# Build VLM messages - simple structure
messages = [
{
"role": "user",
"content": [
{"type": "text", "text": current_instruction},
{"type": "image", "image": image_data} # PIL object
]
},
{
"role": "assistant",
"content": [
{"type": "text", "text": text_data}
]
}
]
# Return dict with messages
return {"messages": messages}
total = len(dataset)
first_image = next(iter(dataset))[image_column]
has_urls = isinstance(first_image, str) and first_image.startswith(("http://", "https://"))
# ── Bare-filename detection: images stored as filenames (e.g. "img_001.png")
# that don't exist locally. Build a basename→repo_path lookup so we can
# resolve them via hf_hub_download during conversion.
_image_lookup = None
_IMAGE_EXTS = ('.png', '.jpg', '.jpeg', '.webp', '.gif', '.bmp', '.tiff')
if (
not has_urls
and isinstance(first_image, str)
and not os.path.exists(first_image)
and dataset_name
):
try:
from huggingface_hub import HfApi
_notify("Resolving image filenames from HF repo...")
print(f"🔍 Image column contains bare filenames (e.g. '{first_image}') — building repo lookup...")
repo_files = HfApi().list_repo_files(dataset_name, repo_type="dataset")
_image_lookup = {
os.path.basename(f): f
for f in repo_files
if any(f.lower().endswith(ext) for ext in _IMAGE_EXTS)
}
if first_image in _image_lookup:
print(f"✅ Matched {len(_image_lookup)} image files in repo (e.g. '{first_image}''{_image_lookup[first_image]}')")
else:
print(f"⚠️ Built lookup with {len(_image_lookup)} images but '{first_image}' not found — falling back to local open")
_image_lookup = None
except Exception as e:
print(f"⚠️ Failed to build HF repo image lookup: {e}")
_image_lookup = None
# ── URL probe: 200 samples with parallel workers to estimate speed + failure rate ──
PROBE_SIZE = 200
MAX_FAIL_RATE = 0.3
if has_urls and total > PROBE_SIZE:
import time
from concurrent.futures import ThreadPoolExecutor, as_completed
from utils.hardware import safe_num_proc
num_workers = safe_num_proc()
_notify(f"Probing {PROBE_SIZE} image URLs with {num_workers} workers...")
print(f"🔍 Probing {PROBE_SIZE}/{total} image URLs with {num_workers} workers...")
probe_samples = [dataset[i] for i in range(PROBE_SIZE)]
probe_ok = 0
probe_fail = 0
probe_start = time.time()
with ThreadPoolExecutor(max_workers=num_workers) as executor:
futures = {executor.submit(_convert_single_sample, s): s for s in probe_samples}
for future in as_completed(futures):
try:
future.result()
probe_ok += 1
except Exception:
probe_fail += 1
probe_elapsed = time.time() - probe_start
probe_total = probe_ok + probe_fail
fail_rate = probe_fail / probe_total if probe_total > 0 else 0
throughput = probe_total / probe_elapsed if probe_elapsed > 0 else 0
if fail_rate >= MAX_FAIL_RATE:
msg = (
f"⚠️ {fail_rate:.0%} of the first {PROBE_SIZE} images failed to download "
f"({probe_fail}/{probe_total}). "
"This dataset has too many broken or unreachable image URLs. "
"Consider using a dataset with embedded images instead."
)
print(msg)
_notify(msg)
raise ValueError(msg)
# Estimate total time for remaining samples
remaining = total - PROBE_SIZE
estimated_seconds = remaining / throughput if throughput > 0 else 0
eta_str = _format_eta(estimated_seconds)
info_msg = (
f"Downloading {total:,} images ({num_workers} workers, ~{throughput:.1f} img/s). "
f"Estimated time: ~{eta_str}"
)
if probe_fail > 0:
info_msg += f" | {fail_rate:.0%} broken URLs will be skipped"
print(f"✅ Probe passed: {probe_ok}/{probe_total} ok, {probe_fail} failed ({fail_rate:.0%}), {throughput:.1f} img/s")
print(f"⏱️ Estimated time for {total:,} samples: ~{eta_str}")
_notify(info_msg)
# ── Full conversion with progress ──
from tqdm import tqdm
print(f"🔄 Converting {total} samples to VLM format...")
converted_list = []
failed_count = 0
if has_urls:
# Parallel conversion for URL-based datasets
import time
from concurrent.futures import ThreadPoolExecutor, as_completed
from utils.hardware import safe_num_proc
num_workers = safe_num_proc()
batch_size = 500
start_time = time.time()
for batch_start in range(0, total, batch_size):
batch_end = min(batch_start + batch_size, total)
batch_samples = [dataset[i] for i in range(batch_start, batch_end)]
with ThreadPoolExecutor(max_workers=num_workers) as executor:
futures = {executor.submit(_convert_single_sample, s): i for i, s in enumerate(batch_samples)}
batch_results = [None] * len(batch_samples)
for future in as_completed(futures):
idx = futures[future]
try:
batch_results[idx] = future.result()
except Exception as e:
failed_count += 1
if failed_count == 1:
print(f"⚠️ First VLM conversion failure: {type(e).__name__}: {e}")
converted_list.extend(r for r in batch_results if r is not None)
# Progress update every batch
elapsed = time.time() - start_time
done = batch_end
rate = done / elapsed if elapsed > 0 else 0
remaining_time = (total - done) / rate if rate > 0 else 0
eta_str = _format_eta(remaining_time)
progress_msg = f"Downloading images: {done:,}/{total:,} ({done*100//total}%) | ~{eta_str} remaining | {failed_count} skipped"
print(f" [{done}/{total}] {rate:.1f} img/s, {failed_count} failed, ETA {eta_str}")
_notify(progress_msg)
else:
# Sequential conversion for local/embedded images (fast, no I/O bottleneck)
pbar = tqdm(dataset, total=total, desc="Converting VLM samples", unit="sample")
for sample in pbar:
try:
converted_list.append(_convert_single_sample(sample))
except Exception as e:
failed_count += 1
if failed_count == 1:
# Log the first failure to aid debugging
print(f"⚠️ First VLM conversion failure: {type(e).__name__}: {e}")
pbar.set_postfix(ok=len(converted_list), failed=failed_count, refresh=False)
pbar.close()
if failed_count > 0:
fail_rate = failed_count / total
print(f"⚠️ Skipped {failed_count}/{total} ({fail_rate:.0%}) samples with broken/unreachable images")
# For datasets that skipped the probe (small URL datasets), check fail rate now
if has_urls and fail_rate >= MAX_FAIL_RATE:
msg = (
f"⚠️ {fail_rate:.0%} of images failed to download ({failed_count}/{total}). "
"This dataset has too many broken or unreachable image URLs. "
"Consider using a dataset with embedded images instead."
)
_notify(msg)
raise ValueError(msg)
if len(converted_list) == 0:
raise ValueError(
f"All {total} samples failed during VLM conversion — no usable images found. "
"This dataset may contain only image URLs that are no longer accessible."
)
print(f"✅ Converted {len(converted_list)}/{total} samples")
_notify(f"Converted {len(converted_list):,}/{total:,} images successfully")
# Return list, NOT Dataset
return converted_list
def convert_llava_to_vlm_format(dataset):
"""
Converts Llava format to standard VLM format.
Llava format:
- messages: [{'content': [{'type': 'image', 'index': 0}, {'type': 'text', 'text': '...'}]}]
- images: [PIL_Image1, PIL_Image2, ...]
Standard VLM format:
- messages: [{'content': [{'type': 'image', 'image': PIL_Image}, {'type': 'text', 'text': '...'}]}]
"""
from PIL import Image
print(f"🔄 Converting {len(dataset)} samples from Llava format to standard VLM format...")
def _convert_single_sample(sample):
"""Convert a single llava sample to standard VLM format."""
messages = sample["messages"]
images = sample.get("images", [])
# Process each message
new_messages = []
for msg in messages:
new_content = []
for item in msg["content"]:
if item["type"] == "image":
# Replace index with actual PIL image
if "index" in item and item["index"] is not None:
img_idx = item["index"]
if img_idx < len(images):
pil_image = images[img_idx]
# Ensure it's PIL
if isinstance(pil_image, str):
pil_image = Image.open(pil_image).convert("RGB")
new_content.append({
"type": "image",
"image": pil_image # Actual PIL object
})
else:
# No index, try to use first image
if len(images) > 0:
pil_image = images[0]
if isinstance(pil_image, str):
pil_image = Image.open(pil_image).convert("RGB")
new_content.append({
"type": "image",
"image": pil_image
})
elif item["type"] == "text":
# Keep text as-is (only type + text)
new_content.append({
"type": "text",
"text": item.get("text", "")
})
new_messages.append({
"role": msg["role"],
"content": new_content
})
return {"messages": new_messages}
# Convert using list comprehension
converted_list = [_convert_single_sample(sample) for sample in dataset]
print(f"✅ Converted {len(converted_list)} samples")
return converted_list