clean etherlab: pep8, E731 do not assign a lambda expression, use a def

clean etherlab: pep8, E203 whitespace before ','

clean etherlab: pep8, E712 comparison to True should be 'if cond is True:' or 'if cond:'

clean etherlab: pep8, E222 multiple spaces after operator

clean etherlab: pep8, E741 ambiguous variable name 'l'

cleanup etherlab: pep8, E306 expected 1 blank line before a nested definition, found X