Python Serverless functions: reducing size of dependencies

Help
1

Hi,
I am trying to use Vercel’s Serverless python functions along with my simple website.

However, the maximum package size allowed by Vercel’s serveless functions is 250 MB, and my python program, despite having only a few packages (Plotly, pandas, etc) surpasses this, with around 360 MB.

Is it possible to somehow decrease the size of the dependencies? Python being an interpreted language, it makes the full package of the dependencies available, since it doesn’t know which functions are going to be needed. Given that I know which functions I need, is there some way to trim down these packages?

Thanks!

2

Hi @astlaan! Here are some tricks that have helped others:

3

Thank you, this seems helpful.

The compilation approach is interesting, however, I am running Windows. I suppose that compiling the python libraries specifically for a Vercel deployment environment will require a different configuration, so that it will support it instead of just my local machine.

Is there any guide on how to do this for the Vercel case?

Thank you

4

How does this differ from using .vercelignore?

How can this exclude help? As far as I know, when deploying in Vercel, the CLI is not uploading the dependencies packages, and Vercel installs the packages itself. Which would make sense since I am running Windows, and I suppose Vercel uses a Linux environment, with could make some C-extended python packages incompatible?.

What would be useful is to allow to drop some files from the dependencies packages during deployment, right after the python packages are installed in Vercel’s Linux requirement.

5

Using the includeFiles and excludeFiles function configuration options and include/exclude files from designated functions. It could be all of them, a subset, or a single function depending on the configurations you set.

Using .vercelignore lets you set files and directories to ignored when uploading your project to Vercel. Sort of like the way .gitignore lets you set files to specify untracked files.

Those are the commonly used options to control function size. I also found some older posts with examples that might help you:

Deploying prebuilt with Vercel CLI could help if you have a way to build locally with reduced function size. I recall others using this in the past for different issues, but I don’t have links to any examples at hand.

6

1) Local build approach

I am having trouble with the local build approach.

(vercel-test) PS C:\Users\user\Documents\Code\project> python --version
Python 3.12.0
(vercel-test) PS C:\Users\user\Documents\Code\project> vercel build
Vercel CLI 37.13.0
Error: Unable to find any supported Python versions.
Learn More: http://vercel.link/python-version
(vercel-test) PS C:\Users\user\Documents\Code\project>

It is saying no supported python versions were found. But as you can see, I used precisely version 3.12, as indicated on the provided link (Using the Python Runtime with Serverless Functions):

image
image815×264 18.3 KB

I found these two pages:

I tried locally installing both nodejs v18 and v20, along with setting that version in package.json (as indicated in the pages, despite my backend being fully in python), but none of this seemed to worked (unless I missed something), I just kept getting the “Unable to find any supported Python versions”. I wish the error was more expressive.

2) Exclude file method

I already removed every single repository file that’s not required for the serverless function.

  1. Does the exclude file method work with the python depedencies packages? Because the bulk of the size comes from this. Let’s say I put some depedencies (ex plotly, pandas) in requirements.txt, and I hit vercel, such that it uploads and is deployed. Will the excludeFiles allow me do drop the files in the plotly/pandas folders that are automatically created by vercel during deployment? Or just files that already existed in the repository pre-deployment?

  2. Is the layout in deployment the same as in .vercel/cache that is created with vercel dev?

7

@amyegan

any input on this?

8

Try setting the Node.js version to 18.x in project settings. If you’re doing anything custom with the files during the build, it might also help to know more about the Build Output API

1 Like
9

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.