Installed packages not recognized while imports work in the console on MacOS

Problem

Attempting to import installed Python packages like sqlalchemy and pyodbc in the editor fails with an error message such as "No module named 'sqlalchemy'." However, imports function correctly when executed in the system terminal.

Cause

This issue may arise due to configuration mismatches between the virtual environment in PyCharm and the system terminal, architecture conflicts (for example, between Rosetta and Apple Silicon environments), or outdated settings.

Resolution

Follow these steps to resolve the issue:

1. Verify Python Interpreter Settings

• Go to File | Settings | Project | Python Interpreter in PyCharm.
• Ensure that the selected interpreter points to the correct virtual environment being used.

2. Check Package Installation

Run the following script in both the PyCharm environment and the system terminal:

import sys, platform, inspect
print("Python:", sys.version)
print("Arch:", platform.machine())
import pyodbc
print("pyodbc:", pyodbc.version)
print("pyodbc .so:", inspect.getfile(pyodbc))

• Make sure the same Python version and architecture (Arch: arm64 or x86_64) are being used in both environments.
• Ensure that package versions are consistent.

3. Recreate Virtual Environment

If the issue persists:

1. Create a new virtual environment using the same Python interpreter.
2. Reinstall sqlalchemy and pyodbc within the new environment using the following commands:

   pip install sqlalchemy pyodbc
   

3. Update the PyCharm project settings to use the new virtual environment.

4. Compile pyodbc from Source (MacOS-Specific)

If architecture mismatches exist or _SQLAllocHandle errors appear during imports, try recompiling pyodbc:

pip uninstall -y pyodbc
export LDFLAGS="-L$(brew --prefix unixodbc)/lib"
export CPPFLAGS="-I$(brew --prefix unixodbc)/include"
pip install --no-binary :all: pyodbc

5. Run Virtual Environment under Rosetta

If drivers are only available for the Intel architecture:

1. Create a wrapper script for the virtual environment:

   > cat .venv/bin/python-x86
   #!/usr/bin/env zsh
   venv=${0:a:h}
   /usr/bin/arch -x86_64 $venv/python "$@"
   

2. Make the script executable:

   chmod +x .venv/bin/python-x86
   

3. Set PyCharm’s interpreter to .venv/bin/python-x86.

6. Restart PyCharm

Restart PyCharm to ensure applied changes take effect.

7. Monitor Recurrent Issues

If the issue resolves and reappears, observe system changes, including updates or environment modifications, and document any patterns. If unresolved, include screenshots and logs for further analysis (while respecting privacy policies).