Update app.py

app.py

@@ -198,8 +198,7 @@ def merge_lines(doc1, doc2, doc3, doc4):
     docs = [doc1, doc2, doc3, doc4]
     merged_lines = []
 
-    with open("merged_lines.txt", "w") as f, \
-            *map(open, docs) as handles:
+    with open("merged_lines.txt", "w") as f, *map(open, docs) as handles:
         for lines in zip(*handles):
             merged_line = "".join(line.strip() for line in lines)
             f.write(merged_line + "\n")