--- a/rename.py	Mon May 31 15:37:50 2021 -0400
+++ b/rename.py	Sat Jun 05 16:32:38 2021 -0400
@@ -1,14 +1,26 @@
-import os
-
-titles = open('list.txt', 'r')
-titlelist = titles.readlines()
-titles.close()
-
-count = 1
-for line in titlelist:
-    line = line.rstrip("\n")
-    if int(count) <= 9:
-        os.rename(f'Lucky☆Star - 0{count}.mkv', f'Lucky☆Star - 0{count} [{line}].mkv')
-    else:
-        os.rename(f'Lucky☆Star - {count}.mkv', f'Lucky☆Star - {count} [{line}].mkv')
-    count += 1
+import os, sys
+
+# valid filename: "[title] - [episode number].mkv"
+for file in os.listdir("./"):
+    if file.endswith(".mkv"):
+        name = file[:-9]
+
+try:
+    throwaway = open(f"{name} - 01.mkv", 'rb')
+except OSError:
+    print(f'Could not open "{name} - 01.mkv". Are you sure the file exists?')
+    sys.exit()
+throwaway.close()
+
+titles = open('list.txt', 'r', encoding='utf-8')
+titlelist = titles.readlines()
+titles.close()
+
+count = 1
+for line in titlelist:
+    line = line.rstrip("\n")
+    if int(count) <= 9:
+        os.rename(f'{name} - 0{count}.mkv', f'{name} - 0{count} [{line}].mkv')
+    else:
+        os.rename(f'{name} - {count}.mkv', f'{name} - {count} [{line}].mkv')
+    count += 1