Fix typos

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Fix loop bounds, upper bound is inclusive

it is exclusive in Python's range()

Signed-off-by: Stefan Marr <git@stefan-marr.de>
There is not 'pass'

Signed-off-by: Stefan Marr <git@stefan-marr.de>
return from wrong level

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Need to call .new()

Signed-off-by: Stefan Marr <git@stefan-marr.de>