Answer: Binary Secret #19

The secret message is:

TAN

Row by row

Row	Bulbs	Add the ‘on’ numbers	Character
1	10100	16 + 4 = 20	T
2	00001	1 = 1	A
3	01110	8 + 4 + 2 = 14	N

Crack it with Python

Python can do the adding for you. int(code, 2) reads a string of 1s and 0s as a binary number. Then the program finds that letter in the alphabet. It takes away 1 because Python counts the letters from 0.

secret = [
    "10100",
    "00001",
    "01110",
]
letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
message = ""
for code in secret:
    number = int(code, 2)
    message = message + letters[number - 1]
print(message)

When you run it, it prints:

TAN