The tools and practices for software development have made substantial improvements over the course of the past decades. The subsequent generations of languages, frameworks and associated coding practices have evolved to improve readability, maintainability and to make the code less errorprone. One of the increasingly prominent paradigms in the latest generation of software development ecosystems is the declarative coding style. From Single Page Applications (SPA) with React, through Infrastructure as Code using Terraform, to declarative idioms in Scala and Haskell, this technique has been increasingly successful in enabling fast development of industrial quality software at scale. In this paper, we introduce PyDeclarative a-a new SPA framework for Python which inherits the best elements of Shiny/Shiny for Python and Qt Modeling Language (QML) in order to allow inline mixing of UI and logic elements; seamless reactive programming with minimal added verbosity; and compositional syntactic uniformity which delivers unparalleled flexibility in Dependency Injection/Inversion of Control mechanisms and refactoring capabilities. We compare our framework against state of the art alternatives in terms of features and performance.