para abril, on encoding

winkey-face.py

import functools

# our goal is to use the format feature of strings to render an array of integers, our encoded message, as a string

## remember character encodings?

# let's load up a fake one
# not a real one, not ascii; a fakeskii

encoding_file = open('zyx-fakeskii', 'r')
fakeskii = encoding_file.read()
encoding_file.close() # ow!

## first we define our core application function

def main(): # that we generally call "main"
    # message is our secret message, hidden in numbers! :)
    message = [  73, 32, 108, 111, 118, 101,  32,  65,  98, 114, 105, 108,  33, 32, 72, 97, 112, 112,
                121, 32,  86,  97, 108, 101, 110, 116, 105, 110, 101,  39, 115, 32, 68, 97, 121,  33 ]
    # if we had to save this message to a physical medium, how might it look? (think: binary)
    print(decode(message, encoding=fakeskii))

## then some helper functions

def decode(message, encoding): # this converts [1, 2, 3] to "abc"
    # you can think of lambdas as even smaller helper functions
    # that have parameters and return values
    # in a smaller syntactic package
    join = lambda z, a: z + a
    prepare_character = lambda char: "{{{0}}}".format(char)
    # map and reduce are very good friends
    return functools.reduce(join, map(prepare_character, message), "").format(*encoding)

# oh yeah, *encoding converts encoding, which exists as an array of characters, as arguments to the function format
# e.g. "".format(*['a', 'b', 'c', 'A', 'B', 'C']) becomes "".format('a', 'b', 'c', ...)

## let's run our program, shall we?

main()

#
# @@@ debug @@@
#
# "fakeskii" like abril just learned what ascii is!
# fixing fakeskii, sorry, no tests for this :P
#
# hint:
#
# fakeskii[33] = "!"
# print(functools.reduce(lambda z, a: z + a, fakeskii)) # z defaults to the first a
#
# just run `python3.7 winkey-face.py > zyx-fakeskii`, tada 🎉
#

#
# nerd stuff: scoping and "hoisting", keyword arguments, lambda calculus, higher-order functions
#

zyx-fakeskii

                                 !     '                         ABCDEFGHIJKLMNOPQRSTUVWXYZ      abcdefghijklmnopqrstuvwxyz

joshuakfarrar$ python3.7 winkey-face.py
I love Abril! Happy Valentine's Day!