使用snowflake-sqlalchemy时出现ImportError：无法导入_rfc_1738_quote

我使用snowflake-sqlalchemy包连接Snowflake，代码如下：

from sqlalchemy import create_engine
engine = create_engine(...)

这段代码之前运行正常，但现在抛出导入异常。尝试切换snowflake-sqlalchemy旧版本后问题仍未解决。

完整错误堆栈：

File "/Users/Etienne.Herlaut/Repositories/python/performance-hub-apps/utils/snowflake.py", line 19, in get_snowflake_connection
    engine = create_engine(f'snowflake://{sf_user}:{sf_password}@{sf_account}?warehouse={wh}&role={role}', connect_args={'timeout': 120})
  File "<string>", line 2, in create_engine
    
  File "/Users/Etienne.Herlaut/.pyenv/versions/3.8.13/lib/python3.8/site-packages/sqlalchemy/util/deprecations.py", line 309, in warned
    return fn(*args, **kwargs)
  File "/Users/Etienne.Herlaut/.pyenv/versions/3.8.13/lib/python3.8/site-packages/sqlalchemy/engine/create.py", line 522, in create_engine
    entrypoint = u._get_entrypoint()
  File "/Users/Etienne.Herlaut/.pyenv/versions/3.8.13/lib/python3.8/site-packages/sqlalchemy/engine/url.py", line 656, in _get_entrypoint
    cls = registry.load(name)
  File "/Users/Etienne.Herlaut/.pyenv/versions/3.8.13/lib/python3.8/site-packages/sqlalchemy/util/langhelpers.py", line 341, in load
    return impl.load()
  File "/Users/Etienne.Herlaut/.pyenv/versions/3.8.13/lib/python3.8/site-packages/importlib_metadata/__init__.py", line 207, in load
    module = import_module(match.group('module'))
  File "/Users/Etienne.Herlaut/.pyenv/versions/3.8.13/lib/python3.8/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1014, in _gcd_import
    
  File "<frozen importlib._bootstrap>", line 991, in _find_and_load
    
  File "<frozen importlib._bootstrap>", line 975, in _find_and_load_unlocked
    
  File "<frozen importlib._bootstrap>", line 671, in _load_unlocked
    
  File "<frozen importlib._bootstrap_external>", line 843, in exec_module
    
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
    
  File "/Users/Etienne.Herlaut/.pyenv/versions/3.8.13/lib/python3.8/site-packages/snowflake/sqlalchemy/__init__.py", line 63, in <module>
    from .util import _url as URL
  File "/Users/Etienne.Herlaut/.pyenv/versions/3.8.13/lib/python3.8/site-packages/snowflake/sqlalchemy/util.py", line 8, in <module>
    from sqlalchemy.engine.url import _rfc_1738_quote
ImportError: cannot import name '_rfc_1738_quote' from 'sqlalchemy.engine.url' (/Users/Etienne.Herlaut/.pyenv/versions/3.8.13/lib/python3.8/site-packages/sqlalchemy/engine/url.py)

这个错误的核心原因是SQLAlchemy与snowflake-sqlalchemy版本不兼容：_rfc_1738_quote是SQLAlchemy的私有内部函数，在新版本SQLAlchemy中被移除/改名，但旧版snowflake-sqlalchemy仍依赖该函数。

解决步骤：

• 固定兼容版本组合
  参考官方版本兼容规则选择匹配的版本：

  • 若用SQLAlchemy 2.0+，需搭配snowflake-sqlalchemy 1.4.0及以上版本
  • 若用SQLAlchemy 1.x，对应snowflake-sqlalchemy 1.3.x及以下版本

• 重新安装指定版本
  先卸载冲突包，再安装兼容组合：

  # 卸载现有包
  pip uninstall snowflake-sqlalchemy sqlalchemy -y
  # 示例：安装适配Python3.8的兼容版本
  pip install snowflake-sqlalchemy==1.4.5 sqlalchemy==2.0.19
  

• 确认虚拟环境
  确保操作的是目标虚拟环境（如你当前使用的pyenv 3.8.13环境），避免全局包冲突。

• 验证修复
  安装完成后运行测试代码：

  from sqlalchemy import create_engine
  # 替换为你的实际连接参数
  engine = create_engine('snowflake://user:password@account?warehouse=wh&role=role')
  with engine.connect() as conn:
      result = conn.execute('SELECT CURRENT_VERSION()')
      print(result.fetchone())
  

内容的提问来源于stack exchange，提问作者Etienne Herlaut