Well, it mostly depend if you live in a sensible district or not. It happens that mostly Arab and black people live in sensible district because they are poorer than the normal average french people. And (relative) poverty is the source of a lot of social problems.

I don't say there is no racism in France too, there is. But it is more indirect, like people trying to avoid looking at black people, or people who prefer helping the white guy instead the black one at school is another example.