That they did, indeed.
And they honestly never really adhered to it either. It was just a knee-jerk reaction to a (I believe Haskell) presentation that said something like "we got n ways to do x", where n was in the double digits and x was something extremely uninteresting like looping over an array.
Can't really recall details though, it was old knowledge by the time I Heard about it around 2010 and a quick Google didn't help me dig it up
While I love Ruby, I was looking forward to some of that "one way to do things" simplicity I'd been promised by Python.
Boy... were my hopes crushed. There are a lot of possible ways to do any given thing, from iteration to package/import structures, etc.
For the most part it seems like the proliferation of options in Python is pretty sane; I can generally see why each choice was made to address existing pain points. So kudos to Python for that. But man, did they leave "one way to do it" behind a loooong time ago.