- import re 
- subject = 'I have a _cat, here is a pic {cat_pic}. Another_pic {cat_figure}' 
- regex = re.compile(r'{[^}]*}|(_)') 
- def myreplacement(m): 
-     if m.group(1): 
-         return "" 
-     else: 
-         return m.group(0) 
- replaced = regex.sub(myreplacement, subject) 
- print(replaced) 
-   
				aW1wb3J0IHJlCnN1YmplY3QgPSAnSSBoYXZlIGEgX2NhdCwgaGVyZSBpcyBhIHBpYyB7Y2F0X3BpY30uIEFub3RoZXJfcGljIHtjYXRfZmlndXJlfScKcmVnZXggPSByZS5jb21waWxlKHIne1tefV0qfXwoXyknKQpkZWYgbXlyZXBsYWNlbWVudChtKToKICAgIGlmIG0uZ3JvdXAoMSk6CiAgICAgICAgcmV0dXJuICIiCiAgICBlbHNlOgogICAgICAgIHJldHVybiBtLmdyb3VwKDApCnJlcGxhY2VkID0gcmVnZXguc3ViKG15cmVwbGFjZW1lbnQsIHN1YmplY3QpCnByaW50KHJlcGxhY2VkKQo=