AWS Lambda Python - How to import modules from local files to app.py

Question

This is a simple SAM-template based deploy with a Docker container. Filesystem structure:

src/app.py
    mymodule.py

In app.py:

from .mymodule import myfunction

Result (on invoke):

Unable to import module 'app': attempted relative import with no known parent package

Removing the dot results in:

Unable to import module 'app': No module named 'mymodule'

Adding the local directory to path does not help either:

import os, sys
currentdir = os.path.dirname(os.path.abspath(__file__))
sys.path.append(currentdir)

Now I guess this appears to be due to the limitations described in the great answer from Relative imports for the billionth time

i.e. app.py is being run as a script, not a module, and scripts cannot import relatively

The workarounds in the above answer both require changing some way the Lambda function is built and/or invoked - how to do this is the question?

Please try from mymodule import ... without dot before mymodule. Ref: stackoverflow.com/Questions/16981921/… — shimo
– shimo, Commented Oct 6, 2021 at 22:49
It then fails with "Unable to import module 'app': No module named 'mymodule'". Have also tried all the sys.path.append() ideas in that answer without any luck. — Dan
– Dan, Commented Oct 7, 2021 at 5:35

jtlz2 · Accepted Answer · 2024-05-23 10:36:41Z

2

Add __init__.py file to your src/ folder (same level as your app.py)

Or if you are using a container, make sure your Dockerfile copies everything and not just app.py

jtlz2

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answered Aug 14, 2022 at 4:23

kib gabriel

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1 Comment

What can I say. It was the Dockerfile. Thanks for taking the time!