Introduce array_to_string() utility function; add port_list property to Service

netbox/utilities/utils.py

@@ -1,6 +1,7 @@
 import datetime
 import json
 from collections import OrderedDict
+from itertools import count, groupby
 
 from django.core.serializers import serialize
 from django.db.models import Count, OuterRef, Subquery
@@ -282,6 +283,16 @@ def curry(_curried_func, *args, **kwargs):
     return _curried
 
 
+def array_to_string(array):
+    """
+    Generate an efficient, human-friendly string from a set of integers. Intended for use with ArrayField.
+    For example:
+        [0, 1, 2, 10, 14, 15, 16] => "0-2, 10, 14-16"
+    """
+    group = (list(x) for _, x in groupby(sorted(array), lambda x, c=count(): next(c) - x))
+    return ', '.join('-'.join(map(str, (g[0], g[-1])[:len(g)])) for g in group)
+
+
 #
 # Fake request object
 #