Cannot find module when executing Python code

I ran this command to install certain Python packages:

pip3 install langchain flask llama_index gradio openai pandas numpy glob2 datetime

As you can see, flask is included.

I then ran my Python code:

python3 embeddings.py

However, I received the following error:

Traceback (most recent call last):
  File "embeddings.py", line 3, in <module>
    from flask import Flask, request, jsonify
ModuleNotFoundError: No module named 'flask'

I'm not sure why, but I went ahead and installed flask again, this time separately using:

pip3 install flask

Then it was missing the next package llama_index. I repeated the same steps.

Essentially, when trying to install multiple Python packages in a single command line, it did not seem to have the desired effect.

So this did not work (in fact, it actually installed only the first package):

pip3 install langchain flask llama_index gradio openai pandas numpy glob2 datetime

And had to install them individual as shown:

pip3 install langchain
pip3 install langchain==0.0.27
pip3 install flask
pip3 install llama_index
pip3 install gradio
pip3 install openai
pip3 install pandas
pip3 install numpy
pip3 install glob2
pip3 install datetime