She said she was convinced the measure would act as a "deterrent".
The law, which bans sexual or sexist comments and degrading, intimidating or hostile behaviour, came as Laguerre, 22, launched a website to allow victims of harassment to recount their ordeal - with 200 posted within 24 hours.
The site, Nous Toutes Harcelement (We are all harassed), aims to collect accounts of incidents "in the street, at work, in the private sphere", she said.
France was appalled when security camera footage from a bar showed her being violently punched by a man in broad daylight after she told him to "shut up" for repeatedly harassing her with lewd advances.
She filed a complaint with police who have opened an investigation, and she wrote that "we must no longer keep quiet".