First of all, if you don't know what pythonic means, see this question.
I love clean code as much as anyone, but I think we all agree that there should be a limit on how much you put on a single line of code.
For example, looking at some examples on the Python wiki I came across elegant one liners like:
# Palindrome Python One-Liner phrase.find(phrase[::-1]) # Find indices of x in a list lst indices = [i for i in range(len(lst)) if lst[i]==x]
but also some others that I don't find that much clean:
# Quicksort Python One-liner lambda L:  if L== else qsort([x for x in L[1:] if x< L]) + L[0:1] + qsort([x for x in L[1:] if x>=L])
Do you have any criteria to limit your one-liners? Or don't you mind about the length of a line as long as it does the work?