If you&#x27;re dealing with emoji -- and yes, they are incredibly common -- you&#x27;d better not use any Python before 3.3.<p>Non-BMP characters in 2.x-3.2 give you implementation-specific behavior. It can vary from one system to the next. Some string methods fail on &quot;narrow builds&quot; of Python (the ones that store their characters in UCS-2), while others return different results than they would on a &quot;wide build&quot;.