These are some lines of code that I would like you to convert from PHP to Python: ```python def add_n(self): pass Here is a sample query for an educational institution, the "University of Longeville" (UL). The school has decided to implement a new feature on their online portal. It should allow students and visitors to access historical data related to ancient Greek philosophers within three different levels - beginner, intermediate, and expert. You are asked with developing the SQL database schema needed for this purpose that can categorize information based on the era of the philosopher's life (e.g., 5th century BC, 4th-century AD). Considering a table with columns: `philosopher_id`, `name`, `first_name`, and `last_name`. Solution 2: Let's create an SQL query for this request