clean-up: fix PEP8 E306 expected 1 blank line before a nested definition, found X

clean-up: fix PEP8 E305 expected 2 blank lines after class or function definition

clean-up: fix PEP8 W391 blank line at end of file

clean-up: fix PEP8 E201 whitespace after '{'

clean-up: fix PEP8 E202 whitespace before ')'

clean-up: fix PEP8 E227 missing whitespace around bitwise or shift operator

clean-up: fix PEP8 E251 unexpected spaces around keyword / parameter equals

clean-up: fix PEP8 E711 comparison to None should be 'if cond is not None:'

clean-up: fix PEP8 E225 missing whitespace around operator

clean-up: fix PEP8 E303 too many blank lines

clean-up: fix PEP8 E231 missing whitespace after ':' or ','

clean-up: fix PEP8 E203 whitespace before ':' and whitespace before ','

clean-up: fix PEP8 E271 multiple spaces after keyword

clean-up: fix PEP8 E261 at least two spaces before inline comment

clean-up: fix PEP8 E302 expected 2 blank lines, found 1