New template tag: hilight which hilights a set of tokens with em tags

inventory/templatetags/hilight.py

@@ -0,0 +1,24 @@
+from django import template
+from django.utils.safestring import mark_safe
+from re import finditer
+
+register = template.Library()
+
+
+@register.filter(name='hilight')
+def hilight(text, tokens):
+    text = str(text)
+    for token in tokens:
+        ltext = text.lower()
+        for token in tokens:
+            positions = []
+            for pos in finditer(token, ltext):
+                positions.append(pos.start())
+            if len(positions) > 0:
+                offset = 0
+                for pos in positions:
+                    start = pos + offset
+                    end = start + len(token)
+                    text = text[:start] + f"<em>{text[start:end]}</em>" + text[end:]
+                    offset += 9
+    return mark_safe(text)