Can I avoid using a database in this scenario?
If you don't need it in a DB, it seems like you could work with the pandas module, and just use it as a DataFrame. The dataframe offers a lot of the easy manipulation of a database without having to actually use a database.
I'm building a web-app with Flask and have an philosophical/architecture related question for all you with more experience than I.
The user enters some basic search criteria in my app, my app then queries multiple 3rd-party APIs for information related to the criteria and aggregates the results. 
Ultimately, my app will send the user a bi-weekly email with an HTML-formatted table containing the information gathered by the API queries (as rows in the table). The information doesn't need to be stored long term, it becomes obsolete after a week or so there is really no point in storing it. The 3rd party APIs will always be queried anew each week or so. 
Initially I was thinking that I would need to maintain a database table for each user which would aggregate and store the results of their specific API queries. I was planning to create the contents of the emailed table from the rows in the database. 
I'm now wondering if there is a way to accomplish all of this without using a database to temporarily  store the results of the API queries before emailing.
My question:  What is the most efficient or optimal means for accomplishing what I'm trying to do? Is it possible to do this without a database for storing the results of the API queries?
To recap here was the sequence of operation for the initial concept:
App queries API for info --> App stores data returned by APIs in DB Table --> App puts info from DB table into formatted HTML table --> App sends HTML table to user in email --> The next time the App queries the APIs the DB tables would be over-written.
For context here are the different packages I'm using:
Flask 1.1.1
werkzeug 0.15.5
Application server for both development and production.
gunicorn 19.9.0
Testing and static analysis.
pytest 5.1.0
pytest-cov 2.7.1
mock 3.0.5
flake8 3.7.8
Data and workers.
psycopg2-binary 2.8.3
Flask-SQLAlchemy 2.4.0
SQLAlchemy 1.3.7
alembic 1.0.11
redis 3.3.7
celery 4.3.0
Forms.
Flask-WTF 0.14.2
WTForms-Components 0.10.4
WTForms-Alchemy 0.16.9
Payments.
stripe 2.35.0
Utils.
faker 2.0.0
Extensions.
flask-debugtoolbar 0.10.1
Flask-Mail 0.9.1
Flask-Login 0.4.1
Flask-Limiter 1.0.1
Flask-Babel 0.12.2
Flask-Static-Digest 0.1.2