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

cleanup etherlab: pep8, E305 expected 2 blank lines after class or function definition, found X

cleanup etherlab: pep8, E201 whitespace after '('

cleanup etherlab: pep8, E202 whitespace before ')'

cleanup etherlab: pep8, E227 missing whitespace around bitwise or shift operator

cleanup etherlab: pep8, E251 unexpected spaces around keyword / parameter equals

cleanup etherlab: pep8, E225 missing whitespace around operator

cleanup etherlab: pep8, E303 too many blank lines (2)