Mention Members using GroupyAPI

MentionExample.py

groupID = "groupID"
targetToTag = "David Teather"

group = client.groups.get(groupID)

def tagMembers(message, mentions):
    loci = [message.index(mentions.name)-1, message.index(mentions.name) + len(mentions.name)-1]
    return attachments.Mentions([loci], [mentions.user_id])

for member in group.members:
    if member.name == targetToTag:
        msg = "epic @" + targetToTag
        att = tagMembers(msg, member)
        group.post(text=msg, attachments=[att])