x, = y (???)

[kj]

I just came across an assignment of the form

  x, = y

where y is a string (in case it matters).

1. What's the meaning of the comma in the LHS of the assignment?
2. How could I have found this out on my own?

(Regarding (2) above, I consulted the index of several Python
reference books but I could not find the answer to (1).  I hope to
find a better Python reference!)

TIA!

kynn

-- 
NOTE: In my address everything before the first period is backwards;
and the last period, and everything after it, should be discarded.