[Bug] fix requirements.txt for example chat-w/-pdf

[LatentDream]

The example is missing some dependencies

To resolve this comment: https://github.com/ploomber/cloud-frontend/pull/601#pullrequestreview-2341988066

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📚 Documentation preview 📚: https://ploomber-doc--284.org.readthedocs.build/en/284/

[neelasha23]

All the dependencies can go in a requirements.lock.txt file. In this file, you can add the specific package that was needed. You can see the format in the other examples

[LatentDream]

requirements.lock.txt this file isn't use by our deployment pipeline. So thus why the missing dependencies.

This is the package installation of a Panel Dockerfile from our platform:

WORKDIR /srv
# Caching Introduced here
COPY requirements.txt /srv/
RUN pip install -r requirements.txt --no-cache-dir

[neelasha23]

Yes the lock file is for debugging purposes. We can just add the specific package required to resolve the issue langchain_community.document_loaders in this file. I'm not sure why all the installed packages need to be mentioned in the requirements.txt file

[neelasha23]

It is mentioned in the error: You can install it using pip install -U langchain-community
So just add langchain-community in this file

[LatentDream]

Isn't the command pip freeze > requirements.txt better? It captures all packages necessary for the app with their versions. This way, future users can build it with the same versions and be sure the app will work.

• Langchain are often breaking api so you need the exact version
• All those requirements are from installing the

panel
openai
chromadb
pypdf
langchain
tiktoken
langchain-community

[neelasha23]

We generally freeze all requirements in the lock file and not the requirements.txt. But maybe @edublancas can suggest?

[edublancas]

there are pros and cons for each approach. in the past, we've created a .lock.txt file and a .txt file. the problem is that the platform only looks at the .txt file.

let's pin dependencies in a .txt file so the platform uses that, but let's only list requirements manually (instead of running pip freeze) because listing everything has the potential to break examples (as there might be packages that are incompatible with Linux or that aren't even needed)

[edublancas]

let's pin versions but only for the explicitly imported packages

[LatentDream]

Fix: 3a3a901