FastAPI开发报错ModuleNotFoundError：找不到sqlalchemy模块的解决方法

使用FastAPI开发API集合，在VS Code中已配置venv虚拟环境并指定Python解释器路径，且已在venv中安装sqlalchemy依赖，但运行代码时仍提示找不到该模块。

相关代码 #

from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

SQLALCHEMY_DATABASE_URL = 'url'
engine = create_engine(SQLALCHEMY_DATABASE_URL)
SessionLocal = sessionmaker(autocommit = False,autoflush=False,bind= engine )

Base = declarative_base()

报错信息 #

Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/multiprocessing/process.py", line 314, in _bootstrap
    self.run()
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/multiprocessing/process.py", line 108, in run
    self._target(*self._args, **self._kwargs)
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/site-packages/uvicorn/_subprocess.py", line 80, in subprocess_started
    target(sockets=sockets)
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/site-packages/uvicorn/server.py", line 65, in run
    return asyncio.run(self.serve(sockets=sockets))
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/asyncio/runners.py", line 194, in run
    return runner.run(main)
           ^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/asyncio/runners.py", line 118, in run
    return self._loop.run_until_complete(task)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "uvloop/loop.pyx", line 1517, in uvloop.loop.Loop.run_until_complete
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/site-packages/uvicorn/server.py", line 69, in serve
    await self._serve(sockets)
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/site-packages/uvicorn/server.py", line 76, in _serve
    config.load()
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/site-packages/uvicorn/config.py", line 434, in load
    self.loaded_app = import_from_string(self.app)
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/site-packages/uvicorn/importer.py", line 22, in import_from_string
    raise exc from None
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/site-packages/uvicorn/importer.py", line 19, in import_from_string
    module = importlib.import_module(module_str)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/importlib/__init__.py", line 90, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1331, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 935, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 995, in exec_module
  File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
  File "/Users/anoop/testpython/main.py", line 7, in <module>
    from database import Base
  File "/Users/anoop/testpython/database.py", line 1, in <module>
    from sqlalchemy import create_engine
ModuleNotFoundError: No module named 'sqlalchemy'

解决步骤 #

• 在VS Code中检查Python解释器，执行以下代码验证当前使用的解释器路径：

  import sys
  print(sys.executable)
  

• 通过指定完整路径重新选择正确的虚拟环境解释器
• 卸载并重装sqlalchemy依赖包
• 重启VS Code，问题解决

内容的提问来源于stack exchange，提问作者Anoop