Flask - Where is the best place to place functional logic?
Most of the codebases you find will have a MVC Structure

M = Model
V = View
C = Controller

Models folder will hold "models", which is basically a fancy term for Classes that have the ability to interact with a particular table in your Relational Database.
Views folder will contain all your html templates, which you can render.
Controllers folder will contain controller, which are basically routes, which are invoked by other services, or your frontend.
It is also a good practice to separate Business/Functional Logic to a folder called Managers. 
Lets say you have a Controller called resource_controller, here you can write the logic for handling the API requests to the routes that pertain to this resource. 
All the business logic for resource_controller should be held in resource_manager. All the retrieval, manipulation of data should be handled by the resource_manager. You would also need a resource model. The job of resource is to perform CRUD operations with the database, and return the necessary data to the resource_manager, which will in turn process the data into information and may pass it to the resource_controller. You can return the processed data from the resource_controller back according to your needs.
You may also have a helper file containing code shared by multiple managers.
I am quite new to flask and have been reading up on the use of Blueprints when creating a new project. I am currently working on a small personal website for myself, however I have some questions on where certain processes should be done.
Say I want to retrieve some blog posts from a database, I can create a model and use this to retrieve all the data I want, however I am currently planning on writing the code to initiate the retrieval of the blog posts within the view route, I have a feeling this is an incorrect way to go about doing this and that as much logic as possible should be removed from the views file...?
If this assumption is true, where would you generally place all the functional logic? Would you create a helper file within the app and have this file be dedicated to handle all custom logic?