unsloth/studio/backend/utils/datasets/format_conversion.py

407 lines
13 KiB
Python

"""
Format conversion utilities for dataset processing.
This module contains functions for converting between dataset formats
(Alpaca, ShareGPT, ChatML) and standardizing chat formats.
"""
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 convert_to_vlm_format(
dataset,
instruction=None,
text_column="text",
image_column="image",
dataset_name=None,
):
"""
Converts simple {image, text} format to VLM messages format.
Returns a LIST, not a HuggingFace Dataset (to preserve PIL Images).
Returns:
list: List of dicts with 'messages' field
"""
from PIL import Image
from datasets import Image as datasets_Image
from .vlm_processing import generate_smart_vlm_instruction
# Cast string image columns (URLs or local paths) to HF Image() type
# so HuggingFace handles downloading, decoding, and caching transparently.
sample_value = next(iter(dataset))[image_column]
if isinstance(sample_value, str):
dataset = dataset.cast_column(image_column, datasets_Image())
# 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 or path)
image_data = sample[image_column]
# Handle image paths
if isinstance(image_data, str):
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}
# Use list comprehension and return the LIST directly
print(f"🔄 Converting {len(dataset)} samples to VLM format...")
converted_list = [_convert_single_sample(sample) for sample in dataset]
print(f"✅ Converted {len(converted_list)} samples")
# 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