def remove(self, elem):
        """Remove a requirement.

        :param elem: a string or :class:`Requirement` instance.
        """
        if isinstance(elem, text_type):
            for requirement in self:
                if requirement.package == elem:
                    return super(Requirements, self).remove(requirement)
        return super(Requirements, self).remove(elem)
def edit_category(category_id):
    category = Category.query.filter_by(id=category_id).first_or_404()

    form = CategoryForm(obj=category)

    if form.validate_on_submit():
        form.populate_obj(category)
        flash(_("Category updated."), "success")
        category.save()

    return render_template("management/category_form.html", form=form,
                           title=_("Edit Category"))