Why isn't Python very good for functional programming? [closed]

Answer 1

Python is almost a functional language. It's "functional lite".

It has extra features, so it isn't pure enough for some.

It also lacks some features, so it isn't complete enough for some.

The missing features are relatively easy to write. Check out posts like this on FP in Python.

Answer 2

Let me demonstrate with a piece of code taken from an answer to a "functional" Python question on SO

Python:

def grandKids(generation, kidsFunc, val):
  layer = [val]
  for i in xrange(generation):
    layer = itertools.chain.from_iterable(itertools.imap(kidsFunc, layer))
  return layer

Haskell:

grandKids generation kidsFunc val =
  iterate (concatMap kidsFunc) [val] !! generation

The main difference here is that Haskell's standard library has useful functions for functional programming: in this case iterate, concat, and (!!)

Answer 3

Another reason not mentioned above is that many built-in functions and methods of built-in types modify an object but do not return the modified object. If those modified objects were returned, that would make functional code cleaner and more concise. For example, if some_list.append(some_object) returned some_list with some_object appended.