Generates combinations of elements in multiple lists. https://repl.it/BrPA/0 https://twitter.com/dela3499/status/704220067387437056

generate_combinations.py

def thread_last(val, *forms):
    """ Thread value through a sequence of functions/forms

    >>> def double(x): return 2*x
    >>> def inc(x):    return x + 1
    >>> thread_last(1, inc, double)
    4

    If the function expects more than one input you can specify those inputs
    in a tuple.  The value is used as the last input.

    >>> def add(x, y): return x + y
    >>> def pow(x, y): return x**y
    >>> thread_last(1, (add, 4), (pow, 2))  # pow(2, add(4, 1))
    32

    So in general
        thread_last(x, f, (g, y, z))
    expands to
        g(y, z, f(x))

    >>> def iseven(x):
    ...     return x % 2 == 0
    >>> list(thread_last([1, 2, 3], (map, inc), (filter, iseven)))
    [2, 4]

    See Also:
        thread_first
    """
    def evalform_back(val, form):
        if callable(form):
            return form(val)
        if isinstance(form, tuple):
            func, args = form[0], form[1:]
            args = args + (val,)
            return func(*args)
    return ft.reduce(evalform_back, forms, val)
    
import itertools as it    
import functools as ft
# from toolz import thread_last
    
def println(x):
    for xi in x: 
        print(xi)

def all_unique(x):
    return len(x) == len(set(x))
        
# List (List String) -> List String
def generate_combinations(xs):
    return thread_last(
        it.product(*xs), 
        (filter, all_unique), # drop repeats
        # (map, lambda x: ' '.join(x)),
        list)

format_string = "Create a {business} around {interest1} and {interest2}."
interests = "golf, generative art, programming, puerto rico".split(', ')
business_models = "subscription, pdf, gadget".split(', ')


keys = ["interest1","interest2","business"]
xs = [interests, interests, business_models]

# String -> List String -> List String -> String
def create_string(format_string, keys, replacements):
    return format_string.format(**dict(zip(keys, replacements)))

strings = [create_string(format_string, keys, replacements) 
            for replacements in generate_combinations(xs)]

println(strings)