Permutate punctuation for test GMails

make_test_gmails.py

#!/usr/bin/env python
import sys

"""
Got the idea from https://learn.lytics.com/understanding/product-docs/lytics-javascript-tag/testing-and-verification#testing-audiences

Given an input of "test", makes:
t.e.s.t.@gmail.com
t.e.s.t@gmail.com
t.e.st.@gmail.com
t.e.st@gmail.com
t.es.t.@gmail.com
t.es.t@gmail.com
t.est.@gmail.com
t.est@gmail.com
te.s.t.@gmail.com
te.s.t@gmail.com
te.st.@gmail.com
te.st@gmail.com
tes.t.@gmail.com
tes.t@gmail.com
test.@gmail.com
test@gmail.com

This list gets exponentially big--7 letters in the name = 128 versions of the
name--so make sure to redirect to a file (I picked a CSV extension so
the list can be loaded and tracked in Excel):

  python make_test_gmails.py test > test_gmails.csv

"""

def binary_puncs(s, _len, puncs):
    if len(s) == _len:
        puncs.append(s)
        return puncs

    puncs = binary_puncs(s + '.', _len, puncs)
    # Encode a space (' ') as a place-holder for not-punctuated, e.g.,
    #   ['.. .', '. . ', ' . .']
    puncs = binary_puncs(s + ' ', _len, puncs)

    return puncs

def make_test_names(name):
    punctuation_sets = binary_puncs('', len(name), [])
    letter_fields = [c for c in name]

    punctuated_names = []
    for punc_set in punctuation_sets:
        punc_fields = [c for c in punc_set]
        component_fields = zip(letter_fields, punc_fields)

        punctuated_name = ''.join(
            [''.join(cf).strip() for cf in component_fields])
        punctuated_names.append(punctuated_name)

    return punctuated_names

def make_test_gmails(punctuated_names):
    gmails = []
    for pn in punctuated_names:
        gmails.append('@'.join([pn, 'gmail.com']))
    return gmails
    
if __name__ == '__main__':
    name = sys.argv[1]
    punctuated_names = make_test_names(name)
    gmails = make_test_gmails(punctuated_names)
    for gmail in gmails:
        print(gmail)