def coerce(cls, string):
        """Create a :class:`Requirement` object from a given package spec."""
        match = re.match(cls.spec_regex, string)
        if not match:
            raise InvalidRequirementSpecError("could not parse requirement")
        package = match.group(1)
        if all(match.group(2, 3)):
            version = "".join(match.group(2, 3))
        else:
            version = None
        return cls(package, version)
def add_group():
    form = AddGroupForm()
    if form.validate_on_submit():
        form.save()
        flash(_("Group added."), "success")
        return redirect(url_for("management.groups"))

    return render_template("management/group_form.html", form=form,
                           title=_("Add Group"))