#urls.py
url(r'^valider/(?P<mot>.+)/', 'valider', name = 'lexique_valider'),

#template:
<a href="{% url lexique_valider word.mot %}" title="Valider {{ word.mot}}">{% trans "valider" %}</a>

erreur:
Template error

In template /home/obselete/Documents/vivafaune/public/site_media/templates/includes/lexique/optionsData.html, error at line 10
Caught NoReverseMatch while rendering: Reverse for 'lexique_valider' with arguments '('',)' and keyword arguments '{}' not found.