Google App Engine - updating an entity

Google App Engine - updating an entity

I'm using Google App Engine 1.8.3 - Python 2.7 and NDB API as my datastore
Suppose I have a list of group entities displayed on a html table. And I
want to click the name of an individual group to edit the group's
information. What should the key/id of this group be, which one should I
use? Please take a look at below
Here's my Model:
class Group(ndb.Model):
name = ndb.StringProperty()
description = ndb.StringProperty()
In my html:
......
{% for group in groups %}
<tr>
<td>
<a href="/editGroup?id={{ ????????????? }}" </a>
</td>
<td>

</td>
</tr>
{% endfor %}
......
In the ????? inside the <a> tag, what should I put? what should I pass it
back to the server? group.key? group.key.id()? or I have to add the
Property to Group model as a key property like groupId =
ndb.IntegerProperty()?
I'm thinking about using the entity's key, but I couldn't find a way to
display the key in the html from 'group', like
group.something_to_get_the_key().
I was able to get the numeric id using group.key.id(), but according to
https://developers.google.com/appengine/docs/python/ndb/entities#numeric_keys
numeric ids might not be unique.
Thanks