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

clean-up: fix PEP8 W293 blank line contains whitespace

clean-up: fix some PEP8 E228 missing whitespace around modulo operator

clean-up: fix some PEP8 E265 block comment should start with '# '

clean-up: fix PEP8 E401 multiple imports on one line