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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def delete_by_user_name(user_name):
        '''
        Delete user in the database by `user_name`.
        '''
        try:
            del_count = TabMember.delete().where(TabMember.user_name == user_name)
            del_count.execute()
            return True
        except:
            return False