Pre-requisits

You can pass functions as variables

def add_two(x):
    return x+2

def do_something_then_add_three(something_to_do_first, x):
    # first call something_to_do_first with the input, then add 3
    return something_to_do_first(x) + 3

# We pass add_two (note the lack of brackets beside it)
do_something_then_add_three(add_two, 0)

5

An iterator is an object representing a stream of data. You can call next on an iterator to get the next value.

from string import ascii_lowercase
ascii_lowercase

'abcdefghijklmnopqrstuvwxyz'

iter(ascii_lowercase)

<str_iterator at 0x7fad0bcb2d10>

alphabet_iterator = iter(ascii_lowercase)
next(alphabet_iterator)

'a'

next(alphabet_iterator)

'b'

def add_underscore(x,y): 
    return f'{x}_{y}'

import itertools
alphabet_iterator = iter(ascii_lowercase)

my_list = [1,3,5,6]
list(itertools.islice(my_list, 3))

[1, 3, 5]

Say we want to create a list of tuples with ( position_in_alphabet, letter ) starting at (1, 'a') like

[(1, 'a'), (2, 'b'), (3, 'c')]

[(1, 'a'), (2, 'b'), (3, 'c')]

alphabet_tuples = []
for i in range(len(ascii_lowercase)):
    alphabet_tuples.append((i+1, ascii_lowercase[i]))  
alphabet_tuples

[(1, 'a'),
 (2, 'b'),
 (3, 'c'),
 (4, 'd'),
 (5, 'e'),
 (6, 'f'),
 (7, 'g'),
 (8, 'h'),
 (9, 'i'),
 (10, 'j'),
 (11, 'k'),
 (12, 'l'),
 (13, 'm'),
 (14, 'n'),
 (15, 'o'),
 (16, 'p'),
 (17, 'q'),
 (18, 'r'),
 (19, 's'),
 (20, 't'),
 (21, 'u'),
 (22, 'v'),
 (23, 'w'),
 (24, 'x'),
 (25, 'y'),
 (26, 'z')]

list(zip(count(start=1), ascii_lowercase))

[(1, 'a'),
 (2, 'b'),
 (3, 'c'),
 (4, 'd'),
 (5, 'e'),
 (6, 'f'),
 (7, 'g'),
 (8, 'h'),
 (9, 'i'),
 (10, 'j'),
 (11, 'k'),
 (12, 'l'),
 (13, 'm'),
 (14, 'n'),
 (15, 'o'),
 (16, 'p'),
 (17, 'q'),
 (18, 'r'),
 (19, 's'),
 (20, 't'),
 (21, 'u'),
 (22, 'v'),
 (23, 'w'),
 (24, 'x'),
 (25, 'y'),
 (26, 'z')]

import IPython.display as ipd
import numpy as np
import itertools

import itertools

def ascii_wav(times=3):
    wave = "°º¤ø,¸¸,ø¤º°`"
    return ''.join(itertools.repeat(wave, times))

ascii_wav()

'°º¤ø,¸¸,ø¤º°`°º¤ø,¸¸,ø¤º°`°º¤ø,¸¸,ø¤º°`'