pythonmongodbflaskpymongovercel

How to use `pymongo` with `flask` inside of Vercel


I want to add database functionalities to my Flask app hosted on Vercel.

When using pymongo the website throws HTTP 500 saying that my app crashed.

It also says that I should check the logs.

The logs say this error:

[ERROR] Runtime.ImportModuleError: Unable to import module 'vc__handler__python': cannot import name 'MutableMapping' from 'collections' (/var/lang/lib/python3.12/collections/__init__.py)
Traceback (most recent call last):INIT_REPORT Init Duration: 1348.16 ms Phase: invoke   Status: error   Error Type: Runtime.Unknown

Maybe pymongo needs to make mutable objects and the Python interpreter on Vercel doesn't have it? I don't know.


Solution

  • From the error message "cannot import name 'MutableMapping' from 'collections'", it seems the code you are running targets an older version of Python. The documentation for Python 3.9 states:

    Deprecated since version 3.3, will be removed in version 3.10: Moved Collections Abstract Base Classes to the collections.abc module. For backwards compatibility, they continue to be visible in this module through Python 3.9.

    Also, ensure that the PyMongo version is compatible with the Python version that you are using. You are using Python 3.12 so the PyMongo version should be 4.5 or higher. Look up the compatibility matrix at: https://www.mongodb.com/docs/languages/python/pymongo-driver/current/compatibility/#language-compatibility . If you have to upgrade your PyMongo version, you can do it with python3 -m pip install --upgrade pymongo