Issue #26581: Use the first coding cookie on a line, not the last one.
diff --git a/Lib/idlelib/IOBinding.py b/Lib/idlelib/IOBinding.py
index ef40715..1233d80 100644
--- a/Lib/idlelib/IOBinding.py
+++ b/Lib/idlelib/IOBinding.py
@@ -65,7 +65,7 @@
 
 encoding = encoding.lower()
 
-coding_re = re.compile(r'^[ \t\f]*#.*coding[:=][ \t]*([-\w.]+)')
+coding_re = re.compile(r'^[ \t\f]*#.*?coding[:=][ \t]*([-\w.]+)')
 blank_re = re.compile(r'^[ \t\f]*(?:[#\r\n]|$)')
 
 class EncodingMessage(SimpleDialog):