---
id: "langchain-import-community-007"
title: "langchain-community 与 langchain-core 版本冲突导致导入失败"
title_en: "langchain-community and langchain-core version conflict causes import failure"
framework: "langchain"
framework_version: ">=0.2.0"
language: "python"
tags:
  - "import-error"
  - "configuration"
severity: "high"
complexity: "simple"
environment:
  python_version: ">=3.9"
  os: "any"
created_at: "2026-03-11"
updated_at: "2026-03-11"
contributors:
  - github: "CyberHuaTuo"
source_url: "https://github.com/langchain-ai/langchain/issues/22456"
related_cases:
  - "langchain-import-chatmodel-001"
---

## 🏥 症状描述
Symptom Description

安装多个 langchain 相关包后，导入任何 langchain 模块都报 `ImportError` 或 `AttributeError`。通常发生在混合安装了不同版本的 `langchain`、`langchain-core`、`langchain-community` 后。

## 🔍 错误信息
Error Message

```python
ImportError: cannot import name 'BaseChatModel' from 'langchain_core.language_models'
```

或

```python
AttributeError: module 'langchain_core' has no attribute 'runnables'
```

或

```
ERROR: pip's dependency resolver does not currently take into account 
all the packages that are installed. langchain-community 0.2.x requires 
langchain-core<0.3.0,>=0.2.0, but you have langchain-core 0.3.1.
```

## 🔬 根因分析
Root Cause Analysis

LangChain 0.3 拆分为多个独立包（`langchain-core`、`langchain-community`、`langchain-openai` 等），它们之间有严格的版本约束。常见原因：
1. 手动单独升级了某个包，破坏了版本兼容性
2. `pip install langchain` 没有同步更新依赖包
3. 环境中残留了旧版本的包

## 💊 药方
Prescriptions

### 药方 1：一键修复所有版本 ✅ 推荐

```bash
# 先卸载所有 langchain 相关包
pip uninstall langchain langchain-core langchain-community langchain-openai langchain-text-splitters -y

# 重新安装（pip 会自动解析兼容版本）
pip install langchain langchain-openai langchain-community
```

### 药方 2：锁定版本安装

```bash
# 使用明确的兼容版本组合
pip install langchain==0.3.7 langchain-core==0.3.15 langchain-community==0.3.7 langchain-openai==0.2.8
```

### 药方 3：检查当前版本

```bash
pip list | grep langchain
```

确保以下包版本兼容：
- `langchain` 和 `langchain-core` 主版本号一致（如都是 0.3.x）
- `langchain-community` 主版本号与 `langchain-core` 匹配

## 🔗 参考资料
References

- [LangChain Package Versioning](https://python.langchain.com/docs/versions/)
- [LangChain 0.3 Changelog](https://github.com/langchain-ai/langchain/releases)

---

> 📝 本药方由 [@CyberHuaTuo](https://github.com/CyberHuaTuo) 贡献
