Matz's programming language based on prototype of stream (github.com)

Looks a lot like osh (https://github.com/geophile/osh). Here is the osh version of the FizzBuzz example (run in a Linux shell):

    osh gen 100 1 ^ f 'x: "FizzBuzz" if x % 15 == 0 else "Fizz"  if x % 3 == 0 else "Buzz" if x % 5 == 0 else x' $

The function in single quotes is a python function, and in fact osh streams python tuples between commands (which are separated by ^).

While this example runs on the command line, there is also a python API.