fizzbuzz.py

either  = lambda a, b:    lambda i: a(i) or b(i)
plus    = lambda a, b:    lambda i: a(i) + b(i)
div     = lambda n:       lambda i: i % n == 0
iff     = lambda c, a, b: lambda i: a(i) if c(i) else b(i)
nothing = lambda x: ''
itself  = lambda x: x
const   = lambda x: lambda i: x

# some hints how it works :)

assert div(3)(0) == True
assert div(3)(1) == False
assert div(3)(2) == False
assert div(3)(3) == True
assert div(3)(4) == False
assert div(3)(5) == False

div2or3 = either(div(2), div(3))
assert div2or3(0) == True
assert div2or3(1) == False
assert div2or3(2) == True
assert div2or3(3) == True
assert div2or3(4) == True
assert div2or3(5) == False

# the fizzbuzz

fizz = iff(div(3), const('Fizz'), nothing)
buzz = iff(div(5), const('Buzz'), nothing)
fizzbuzz = either(plus(fizz, buzz), itself)

for i in range(1, 20):
    print(fizzbuzz(i))

output.txt

1
2
Fizz
4
Buzz
Fizz
7
8
Fizz
Buzz
11
Fizz
13
14
FizzBuzz
16
17
Fizz
19