You can try to use a GIS software such as ArcGIS Pro.

https://pro.arcgis.com/en/pro-app/help/editing/create-polygon-features.htm

Without knwing waht kind of features you want is dificult to give a precise advise

In any case I think you can try scikit-image python library is quite intutive and easy to use:

https://scikit-image.org/

al Scipy has lot of tools

Here there is a tutorial of over 2 h where you can learn the basics of this libraries. with the corresponding jupyter notebook in the description of the video:

https://www.youtube.com/watch?v=d1CIV9irQAY

I recomend to dwonload and save python objects as arrays list or other similar things using Pickle package. You can load them later frot further use.

If you want to save an array from numpy to other format used np.savetxt()

https://numpy.org/doc/stable/reference/generated/numpy.savetxt.html

alternatively you can used pandas to manipulate arrays and save them with dataFrame.to_csv() (pandas is build on top of np and very powerfull)

chek here:

https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.to_csv.html

if not for python question i recomend stackoverflow, they are answers for everything:

https://stackoverflow.com/

cheers and i hope I help you

Noor ul ain Ibrahim You can put the features in a NumPy array then save it to a binary file in NumPy .npy format.

See Documentation: https://numpy.org/doc/stable/reference/generated/numpy.save.html