fixed pep8 complaints E711, E712, E713
fixed pep8 complaints E202, E203, E225, E231, E302, W293

E202 whitespace before ')'
E203 whitespace before ','
E225 missing whitespace around operator
E231 missing whitespace after ','
E302 expected 2 blank lines, found 1
W293 blank line contains whitespace
fixed pep8 complaint 'W291 trailing whitespace'