Object-oriented and functional programming styles can be combined within the same codebase by extracting methods that do not require shared mutable state out of a class into standalone functions, leaving classes to serve primarily as data structures. Function composition, implemented via a compose/apply/reduce mechanism, allows a sequence of unary transformations to be chained into a single callable, replacing deeply nested function calls with a linear, more readable pipeline. This relates to core functional-programming and software-design concepts: pure functions (no side effects, easier to test and reuse), higher-order functions (functions that accept or return other functions), closures (inner functions that retain access to variables in an enclosing scope), and type aliases for callables — all of which belong to the broader discipline of software design and functional programming as applied within an object-oriented language like Python.
Object-oriented and functional programming styles can be combined within the same codebase by extracting methods that do not require shared mutable state out of a class into standalone functions, lea…