French ex-president Sarkozy begins jail sentence

By the way, this is not possible in the U.S and in many other countries. When someone is convicted of a crime, they don’t usually start serving a prison sentence until the case is final. If they appeal, the sentence is automatically paused or can be stayed by the court. In practice, this means you don’t go to prison (unless you are already in preventive detention because of flight risk or danger) while your case is still being fought in higher courts.

It needs to be noted that it's not the norm in France either. The court chose to send him to jail until the appeal because of the "exceptional gravity" of his behavior, which came to a surprise for many. He will most likely ask the courts to review the execution of the sentence until the appeal in the next few days.