web_support.py: make_list: don't subscript the list

We may get objects that are not subscriptable in py3, such as
map objects, so just iterate over the whole object and pop the
last separator instead.

1 files changed, 5 insertions, 5 deletions

diff --git a/lib/python/web_support.py b/lib/python/web_support.py
index 50d62757e8..1ad6a7f51f 100644
--- a/lib/python/web_support.py
+++ b/lib/python/web_support.py
@@ -527,11 +527,11 @@ def make_list(lst, separator=", "):
     assert not isstring(lst)
     c = []
     if lst:
-        append = c.append
-        for e in lst[:-1]:
-            append(e)
-            append(separator)
-        append(lst[-1])
+        for e in lst:
+            c.append(e)
+            c.append(separator)
+        # pop the final separator
+        c.pop()
     return Compose(c)
 
 class InvalidPath(Exception):