Outlines
在生成过程中保证有效的 JSON/XML/代码结构,使用 Pydantic 模型实现类型安全的输出,支持本地模型(Transformers, vLLM),并通过 Outlines(dottxt.ai 的结构化生成库)最大化推理速度
技能元数据
| 来源 | 捆绑包(默认安装) |
| 路径 | skills/mlops/inference/outlines |
| 版本 | 1.0.0 |
| 作者 | Orchestra Research |
| 许可证 | MIT |
| 依赖项 | outlines, transformers, vllm, pydantic |
| 标签 | Prompt Engineering, Outlines, Structured Generation, JSON Schema, Pydantic, Local Models, Grammar-Based Generation, vLLM, Transformers, Type Safety |
参考:完整 SKILL.md
信息
以下是 Hermes 在触发此技能时加载的完整技能定义。这是技能激活时代理看到的指令。
Outlines:结构化文本生成
何时使用此技能
当您需要执行以下操作时,请使用 Outlines:
- 保证生成过程中有效的 JSON/XML/代码结构
- 使用 Pydantic 模型实现类型安全的输出
- 支持本地模型(Transformers, llama.cpp, vLLM)
- 通过零开销结构化生成最大化推理速度
- 针对 JSON schema 自动生成
- 在语法级别控制 token 采样
GitHub Stars: 8,000+ | 来自: dottxt.ai (前身为 .txt)
安装
# Base installation
pip install outlines
# With specific backends
pip install outlines transformers # Hugging Face models
pip install outlines llama-cpp-python # llama.cpp
pip install outlines vllm # vLLM for high-throughput
快速入门
基本示例:分类
import outlines
from typing import Literal
# Load model
model = outlines.models.transformers("microsoft/Phi-3-mini-4k-instruct")
# Generate with type constraint
prompt = "Sentiment of 'This product is amazing!': "
generator = outlines.generate.choice(model, ["positive", "negative", "neutral"])
sentiment = generator(prompt)
print(sentiment) # "positive" (guaranteed one of these)
配合 Pydantic 模型使用
from pydantic import BaseModel
import outlines
class User(BaseModel):
name: str
age: int
email: str
model = outlines.models.transformers("microsoft/Phi-3-mini-4k-instruct")
# Generate structured output
prompt = "Extract user: John Doe, 30 years old, john@example.com"
generator = outlines.generate.json(model, User)
user = generator(prompt)
print(user.name) # "John Doe"
print(user.age) # 30
print(user.email) # "john@example.com"
核心概念
1. 约束 Token 采样
Outlines 使用有限状态机(FSM)在 logit 级别约束 token 生成。
工作原理:
- 将 schema(JSON/Pydantic/正则表达式)转换为上下文无关文法(CFG)
- 将 CFG 转换为有限状态机(FSM)
- 在生成过程中的每一步过滤无效 token
- 当只有一个有效 token 时快进
优势:
- 零开销:过滤发生在 token 级别
- 速度提升:沿确定性路径快进
- 保证有效性:不可能产生无效输出
import outlines
# Pydantic model -> JSON schema -> CFG -> FSM
class Person(BaseModel):
name: str
age: int
model = outlines.models.transformers("microsoft/Phi-3-mini-4k-instruct")
# Behind the scenes:
# 1. Person -> JSON schema
# 2. JSON schema -> CFG
# 3. CFG -> FSM
# 4. FSM filters tokens during generation
generator = outlines.generate.json(model, Person)
result = generator("Generate person: Alice, 25")
2. 结构化生成器
Outlines 为不同的输出类型提供专用生成器。
Choice 生成器
# Multiple choice selection
generator = outlines.generate.choice(
model,
["positive", "negative", "neutral"]
)
sentiment = generator("Review: This is great!")
# Result: One of the three choices
JSON 生成器
from pydantic import BaseModel
class Product(BaseModel):
name: str
price: float
in_stock: bool
# Generate valid JSON matching schema
generator = outlines.generate.json(model, Product)
product = generator("Extract: iPhone 15, $999, available")
# Guaranteed valid Product instance
print(type(product)) # <class '__main__.Product'>
正则表达式生成器
# Generate text matching regex
generator = outlines.generate.regex(
model,
r"[0-9]{3}-[0-9]{3}-[0-9]{4}" # Phone number pattern
)
phone = generator("Generate phone number:")
# Result: "555-123-4567" (guaranteed to match pattern)
整数/浮点数生成器
# Generate specific numeric types
int_generator = outlines.generate.integer(model)
age = int_generator("Person's age:") # Guaranteed integer
float_generator = outlines.generate.float(model)
price = float_generator("Product price:") # Guaranteed float
3. 模型后端
Outlines 支持多种本地和基于 API 的后端。
Transformers (Hugging Face)
import outlines
# Load from Hugging Face
model = outlines.models.transformers(
"microsoft/Phi-3-mini-4k-instruct",
device="cuda" # Or "cpu"
)
# Use with any generator
generator = outlines.generate.json(model, YourModel)
llama.cpp
# Load GGUF model
model = outlines.models.llamacpp(
"./models/llama-3.1-8b-instruct.Q4_K_M.gguf",
n_gpu_layers=35
)
generator = outlines.generate.json(model, YourModel)
vLLM (高吞吐量)
# For production deployments
model = outlines.models.vllm(
"meta-llama/Llama-3.1-8B-Instruct",
tensor_parallel_size=2 # Multi-GPU
)
generator = outlines.generate.json(model, YourModel)
OpenAI (有限支持)
# Basic OpenAI support
model = outlines.models.openai(
"gpt-4o-mini",
api_key="your-api-key"
)
# Note: Some features limited with API models
generator = outlines.generate.json(model, YourModel)
4. Pydantic 集成
Outlines 提供一流的 Pydantic 支持,具备自动 schema 转换功能。
基本模型
from pydantic import BaseModel, Field
class Article(BaseModel):
title: str = Field(description="Article title")
author: str = Field(description="Author name")
word_count: int = Field(description="Number of words", gt=0)
tags: list[str] = Field(description="List of tags")
model = outlines.models.transformers("microsoft/Phi-3-mini-4k-instruct")
generator = outlines.generate.json(model, Article)
article = generator("Generate article about AI")
print(article.title)
print(article.word_count) # Guaranteed > 0
嵌套模型
class Address(BaseModel):
street: str
city: str
country: str
class Person(BaseModel):
name: str
age: int
address: Address # Nested model
generator = outlines.generate.json(model, Person)
person = generator("Generate person in New York")
print(person.address.city) # "New York"
枚举和字面量
from enum import Enum
from typing import Literal
class Status(str, Enum):
PENDING = "pending"
APPROVED = "approved"
REJECTED = "rejected"
class Application(BaseModel):
applicant: str
status: Status # Must be one of enum values
priority: Literal["low", "medium", "high"] # Must be one of literals
generator = outlines.generate.json(model, Application)
app = generator("Generate application")
print(app.status) # Status.PENDING (or APPROVED/REJECTED)
常见模式
模式 1:数据提取
from pydantic import BaseModel
import outlines
class CompanyInfo(BaseModel):
name: str
founded_year: int
industry: str
employees: int
model = outlines.models.transformers("microsoft/Phi-3-mini-4k-instruct")
generator = outlines.generate.json(model, CompanyInfo)
text = """
Apple Inc. was founded in 1976 in the technology industry.
The company employs approximately 164,000 people worldwide.
"""
prompt = f"Extract company information:\n{text}\n\nCompany:"
company = generator(prompt)
print(f"Name: {company.name}")
print(f"Founded: {company.founded_year}")
print(f"Industry: {company.industry}")
print(f"Employees: {company.employees}")
模式 2:分类
from typing import Literal
import outlines
model = outlines.models.transformers("microsoft/Phi-3-mini-4k-instruct")
# Binary classification
generator = outlines.generate.choice(model, ["spam", "not_spam"])
result = generator("Email: Buy now! 50% off!")
# Multi-class classification
categories = ["technology", "business", "sports", "entertainment"]
category_gen = outlines.generate.choice(model, categories)
category = category_gen("Article: Apple announces new iPhone...")
# With confidence
class Classification(BaseModel):
label: Literal["positive", "negative", "neutral"]
confidence: float
classifier = outlines.generate.json(model, Classification)
result = classifier("Review: This product is okay, nothing special")
模式 3:结构化表单
class UserProfile(BaseModel):
full_name: str
age: int
email: str
phone: str
country: str
interests: list[str]
model = outlines.models.transformers("microsoft/Phi-3-mini-4k-instruct")
generator = outlines.generate.json(model, UserProfile)
prompt = """
Extract user profile from:
Name: Alice Johnson
Age: 28
Email: alice@example.com
Phone: 555-0123
Country: USA
Interests: hiking, photography, cooking
"""
profile = generator(prompt)
print(profile.full_name)
print(profile.interests) # ["hiking", "photography", "cooking"]
模式 4:多实体提取
class Entity(BaseModel):
name: str
type: Literal["PERSON", "ORGANIZATION", "LOCATION"]
class DocumentEntities(BaseModel):
entities: list[Entity]
model = outlines.models.transformers("microsoft/Phi-3-mini-4k-instruct")
generator = outlines.generate.json(model, DocumentEntities)
text = "Tim Cook met with Satya Nadella at Microsoft headquarters in Redmond."
prompt = f"Extract entities from: {text}"
result = generator(prompt)
for entity in result.entities:
print(f"{entity.name} ({entity.type})")
模式 5:代码生成
class PythonFunction(BaseModel):
function_name: str
parameters: list[str]
docstring: str
body: str
model = outlines.models.transformers("microsoft/Phi-3-mini-4k-instruct")
generator = outlines.generate.json(model, PythonFunction)
prompt = "Generate a Python function to calculate factorial"
func = generator(prompt)
print(f"def {func.function_name}({', '.join(func.parameters)}):")
print(f' """{func.docstring}"""')
print(f" {func.body}")
模式 6:批处理
def batch_extract(texts: list[str], schema: type[BaseModel]):
"""Extract structured data from multiple texts."""
model = outlines.models.transformers("microsoft/Phi-3-mini-4k-instruct")
generator = outlines.generate.json(model, schema)
results = []
for text in texts:
result = generator(f"Extract from: {text}")
results.append(result)
return results
class Person(BaseModel):
name: str
age: int
texts = [
"John is 30 years old",
"Alice is 25 years old",
"Bob is 40 years old"
]
people = batch_extract(texts, Person)
for person in people:
print(f"{person.name}: {person.age}")
后端配置
Transformers
import outlines
# Basic usage
model = outlines.models.transformers("microsoft/Phi-3-mini-4k-instruct")
# GPU configuration
model = outlines.models.transformers(
"microsoft/Phi-3-mini-4k-instruct",
device="cuda",
model_kwargs={"torch_dtype": "float16"}
)
# Popular models
model = outlines.models.transformers("meta-llama/Llama-3.1-8B-Instruct")
model = outlines.models.transformers("mistralai/Mistral-7B-Instruct-v0.3")
model = outlines.models.transformers("Qwen/Qwen2.5-7B-Instruct")
llama.cpp
# Load GGUF model
model = outlines.models.llamacpp(
"./models/llama-3.1-8b.Q4_K_M.gguf",
n_ctx=4096, # Context window
n_gpu_layers=35, # GPU layers
n_threads=8 # CPU threads
)
# Full GPU offload
model = outlines.models.llamacpp(
"./models/model.gguf",
n_gpu_layers=-1 # All layers on GPU
)
vLLM (生产环境)
# Single GPU
model = outlines.models.vllm("meta-llama/Llama-3.1-8B-Instruct")
# Multi-GPU
model = outlines.models.vllm(
"meta-llama/Llama-3.1-70B-Instruct",
tensor_parallel_size=4 # 4 GPUs
)
# With quantization
model = outlines.models.vllm(
"meta-llama/Llama-3.1-8B-Instruct",
quantization="awq" # Or "gptq"
)
最佳实践
1. 使用具体类型
# ✅ Good: Specific types
class Product(BaseModel):
name: str
price: float # Not str
quantity: int # Not str
in_stock: bool # Not str
# ❌ Bad: Everything as string
class Product(BaseModel):
name: str
price: str # Should be float
quantity: str # Should be int
2. 添加约束
from pydantic import Field
# ✅ Good: With constraints
class User(BaseModel):
name: str = Field(min_length=1, max_length=100)
age: int = Field(ge=0, le=120)
email: str = Field(pattern=r"^[\w\.-]+@[\w\.-]+\.\w+$")
# ❌ Bad: No constraints
class User(BaseModel):
name: str
age: int
email: str
3. 对类别使用枚举
# ✅ Good: Enum for fixed set
class Priority(str, Enum):
LOW = "low"
MEDIUM = "medium"
HIGH = "high"
class Task(BaseModel):
title: str
priority: Priority
# ❌ Bad: Free-form string
class Task(BaseModel):
title: str
priority: str # Can be anything
4. 在提示词中提供上下文
# ✅ Good: Clear context
prompt = """
Extract product information from the following text.
Text: iPhone 15 Pro costs $999 and is currently in stock.
Product:
"""
# ❌ Bad: Minimal context
prompt = "iPhone 15 Pro costs $999 and is currently in stock."
5. 处理可选字段
from typing import Optional
# ✅ Good: Optional fields for incomplete data
class Article(BaseModel):
title: str # Required
author: Optional[str] = None # Optional
date: Optional[str] = None # Optional
tags: list[str] = [] # Default empty list
# Can succeed even if author/date missing
与替代方案比较
| 特性 | Outlines | Instructor | Guidance | LMQL |
|---|---|---|---|---|
| Pydantic 支持 | ✅ 原生 | ✅ 原生 | ❌ 无 | ❌ 无 |
| JSON Schema | ✅ 是 | ✅ 是 | ⚠️ 有限 | ✅ 是 |
| 正则表达式约束 | ✅ 是 | ❌ 无 | ✅ 是 | ✅ 是 |
| 本地模型 | ✅ 完整 | ⚠️ 有限 | ✅ 完整 | ✅ 完整 |
| API 模型 | ⚠️ 有限 | ✅ 完整 | ✅ 完整 | ✅ 完整 |
| 零开销 | ✅ 是 | ❌ 否 | ⚠️ 部分 | ✅ 是 |
| 自动重试 | ❌ 无 | ✅ 是 | ❌ 无 | ❌ 无 |
| 学习曲线 | 低 | 低 | 低 | 高 |
何时选择 Outlines:
- 使用本地模型(Transformers, llama.cpp, vLLM)
- 需要最大推理速度
- 想要 Pydantic 模型支持
- 需要零开销结构化生成
- 控制 token 采样过程
何时选择替代方案:
- Instructor:需要带有自动重试功能的 API 模型
- Guidance:需要 token healing 和复杂工作流
- LMQL:偏好声明式查询语法
性能特征
速度:
- 零开销:结构化生成的速度与无约束生成一样快
- 快进优化:跳过确定性 token
- 比生成后验证方法快 1.2-2 倍
内存:
- 每个 schema 的 FSM 仅编译一次(缓存)
- 运行时开销极小
- 与 vLLM 配合使用可实现高吞吐量
准确性:
- 100% 有效输出(由 FSM 保证)
- 无需重试循环
- 确定性 token 过滤
资源
- 文档:https://outlines-dev.github.io/outlines
- GitHub:https://github.com/outlines-dev/outlines(8k+ stars)
- Discord:https://discord.gg/R9DSu34mGd
- 博客:https://blog.dottxt.co
另见
references/json_generation.md- 全面的 JSON 和 Pydantic 模式references/backends.md- 特定于后端的配置references/examples.md- 生产就绪示例