Python 3 issue with re

Python 3 interprets string literals as Unicode strings, and therefore \s is treated as an escaped Unicode character.

Declare RegEx pattern as a raw string instead by prepending r

frappe/utils/file_manager.py

@@ -418,7 +418,7 @@ def extract_images_from_html(doc, content):
 		return '<img src="{file_url}"'.format(file_url=file_url)
 
 	if content:
-		content = re.sub('<img[^>]*src\s*=\s*["\'](?=data:)(.*?)["\']', _save_file, content)
+		content = re.sub(r'<img[^>]*src\s*=\s*["\'](?=data:)(.*?)["\']', _save_file, content)
 
 	return content