No. Once is enough.

1 is one time unit long and 000 is three units long. That's why. The bitrate doesn't change in a single message in this kata. Go to the next one in the series for a more complex one.

I don't get why "10001" should unumbiguously translate to ". ."

The instructions state "
if you have trouble discerning if the particular sequence of 1's is a dot or a dash, assume it's a dot.
"
But it does not say anything for a troubling sequence of 0.

Here "000" can be a dot/dash separator with a bitrate of 3 or a letter separator with bitrate of 1 or a faulty word separator.

I see from the answers that everyone assumes a letter separator...

Besides, if the bit code does not make sense, it does not seem a good idea to fall back to an arbitrary decoding that would not make sense either. Why guessing? The program should instead gracefully fail IMO.

A lot of simple problems together makes a complicated one, not a complex one...

More frustating than challenging. The difficulty comes mainly from understanding the instructions that are quite counterintuitive.

Since string is a standard module, it should not be used as a variable name, no?