Answer: Binary Secret #141

The secret message is:

SWIM

Row by row

Row	Bulbs	Add the ‘on’ numbers	Character
1	10011	16 + 2 + 1 = 19	S
2	10111	16 + 4 + 2 + 1 = 23	W
3	01001	8 + 1 = 9	I
4	01101	8 + 4 + 1 = 13	M

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 = [
    "10011",
    "10111",
    "01001",
    "01101",
]
letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
message = ""
for code in secret:
    number = int(code, 2)
    message = message + letters[number - 1]
print(message)

When you run it, it prints:

SWIM