Python StrEnum 与 Literal 的区别

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from enum import StrEnum
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class Status(StrEnum):
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    PENDING = "pending"
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    SUCCESS = "success"
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    FAILED = "failed"

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status = Status.PENDING
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print(status)          # pending
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print(status.value)    # pending

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for s in Status:
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    print(s)

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if status == Status.PENDING:
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    ...

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from typing import Literal
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Status = Literal[
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    "pending",
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    "success",
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    "failed"
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]

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def update_status(
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    status: Status
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):
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    ...

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update_status("pending")  # ✅
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update_status("abc")      # ❌ 类型检查报错

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print(Status)

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typing.Literal['pending', 'success', 'failed']

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from enum import StrEnum
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class ModelProvider(StrEnum):
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    OPENAI = "openai"
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    ANTHROPIC = "anthropic"
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    GEMINI = "gemini"

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from pydantic import BaseModel
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class Request(BaseModel):
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    provider: ModelProvider

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{
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  "enum": [
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    "openai",
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    "anthropic",
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    "gemini"
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  ]
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}

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if req.provider == ModelProvider.OPENAI:
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    ...

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def create_message(
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    role: Literal[
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        "user",
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        "assistant",
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        "system"
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    ]
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):
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    ...