Python: Muli-level if statement on one line

I saw an answer for this on StackExchange, but nobody seemed to understand why it was desirable... (I'm not enough of a participant in StackExchange to have enough reputation points to post a comment there.)

How can I combine multiple if statements onto a single line? I want

if x > 89:
    y = 'A'
elif x > 79:
   y = 'B'
...
else:
   y = 'F'

on a single line.

Yes, it can be done. Yes, it doing so does serve a purpose. Consider the lambda.

lambda x: 'A' if x>89 else 'B' if x>79 else 'C' if x > 69 else 'D' if x > 59 else 'F'