It's not a problem, it is just going by the pep8 guidelines. If you put your cursor on any of the lines, the status bar will tell you the problem. Looking at your screenshot, it says PEP 8 W191. You can disable individual pep8 rules by adding them to your user preferences:
"E225","E231","E501", "E502", "E301", "E302", "E303", "W292", "W293"
For example, I don't like pep8 telling me how to space my code so that is what my preferences look like.
So for you, just add "W191" to the pep8_ignore.