Line 6: outer() passes inner() back as its return value.

Lines 2 to 3: outer() defines a local function inner().

inner at 0x7f18bc85faf0> 12 > function () 13 I am function inner()! 14 15 > outer ()() 16 I am function inner()! 8 9 > function = outer () 10 > function 11. # Function outer() returns function inner() 6. While it’s true that an in-depth description of functional programming is somewhat complex, the goal here isn’t to present a rigorous definition but to show you what you can do by way of functional programming in Python. Python, by contrast, does support functional programming but contains features of other programming models as well. In some languages, virtually all code follows the functional paradigm. Many programming languages support some degree of functional programming.

Parallelizable: Routines that don’t cause side effects can more easily run in parallel with one another.

That eliminates the possibility of side effects, which facilitates debugging.

Transparent: The behavior of a pure function depends only on its inputs and outputs, without intermediary values.

Single statements tend to be concise but pack a lot of punch.

High level: You’re describing the result you want rather than explicitly specifying the steps required to get there.

The functional paradigm is popular because it offers several advantages over other programming paradigms. Computation proceeds by nested or composed function calls, without changes to state or mutable data. In functional programming, a program consists entirely of evaluation of pure functions. What Is Functional Programming?Ī pure function is a function whose output value follows solely from its input values, without any observable side effects. Free Bonus: 5 Thoughts On Python Mastery, a free course for Python developers that shows you the roadmap and the mindset you’ll need to take your Python skills to the next level.

Haskell functional programming tutorial