Style: follow PEP8
diff --git a/scripts/assemble_changelog.py b/scripts/assemble_changelog.py
index 3d82c11..616978e 100755
--- a/scripts/assemble_changelog.py
+++ b/scripts/assemble_changelog.py
@@ -113,7 +113,7 @@
             elif level == 3 and level_2_seen == 1:
                 current_section = content
                 self.section_content.setdefault(content, [])
-            elif level_2_seen == 1 and current_section != None:
+            elif level_2_seen == 1 and current_section is not None:
                 if line.strip():
                     self.section_content[current_section].append(line)
             elif level_2_seen <= 1: