is there a simple way to get group names of a user in django

You can get the groups of a user with request.user.groups.all(), which will return a QuerySet. And then you can turn that object into a list if you want.

for g in request.user.groups.all():
    l.append(g.name)

or with recent Django

l = request.user.groups.values_list('name',flat = True) # QuerySet Object
l_as_list = list(l)                                     # QuerySet to `list`

user.groups.all()[0].name == "groupname"

This is better

if user.groups.filter(name='groupname').exists():
    # Action if existing

else:
    # Action if not existing