I want to publish an e-book on amazon. I have a file story.txt and ten pictures (picture1, picture2, picture3, etc..) what would a python script need in order to convert my files into a kindle format?
First I'll point out that you may not need a python script to accomplish this task. See the Kindle book creation guide for more information: https://kdp.amazon.com/en_US/help/topic/G202172740

If you provide me with the content of the txt file and location of the images, with their filenames and alternate text descriptions (for screen reader compatibility), I can convert those to an html file which is ready for uploading to Kindle's publishing platform.

Pandoc is a popular utility for converting between text file formats, and there is a python library called pypandoc which wraps this utility nicely.

Finally, if you want to accomplish your task with a python script, update your txt file at the locations the images should be inserted following this example:

Insert picture1.png
An alt-text description of picture 1.

Then install pypandoc and run code following this example:

import pypandoc
output = pypandoc.convert_file('story.txt', 'epub', outputfile="story.epub")
assert output == ""