Transitioning from LpSolve to Gurobi - Need Help Building Model 4 layers

Hi Team,

I'm transitioning from LpSolve in R to Gurobi in Python because of its computational power and capabilities. I've also convinced some clients to use Gurobi for its advantages.

However, as a Gurobi beginner, I'm facing challenges in building the model despite watching training videos and exploring code examples for the past two days.

Problem Description:

I'm aiming to maximize the net revenue of third-party companies after accounting for advertising spending costs. Their net revenue is based on commissions received from brands/suppliers.

Key Metrics:

• GMV: Gross Merchandising Value
• NMV: Net Merchandising Value (after cancellation/return)
• pct_cms_nmv: Commission percentage (received from brand/suppliers) (calculated on NMV)
• pct_ml_sharing: Proportion of commission received by the company (e.g., 100% for full-time employees)
• pct_ad_gmv: GMV generated through Ads
• roas: Return on Ads Spend

Net Revenue Formula:

Net Revenue = gmv * pct_nmv * pct_cms_nmv * pct_ml_sharing - (pct_ads_gmv * gmv) / roas

Modeling Challenges:

• Structure: I'm having difficulty formulating the problem considering four layers: creator_type, class, content_type, and category. Each combination has different commission rates and other values.
• Objective Function: While I've seen examples using single indices (I, j), I'm unsure how to define the objective function with relevant coefficients for the four-layer structure.
• Constraints: I'm particularly interested in building constraints that focus only on full-time creators (creator_type) and live stream content (class). However, I'm unsure of the syntax for this.

Request for Assistance:

I'd greatly appreciate your help in overcoming this steep learning curve. Specifically, I would be grateful for guidance on:

• Building the model considering the four-layer structure.
• Defining the objective function with relevant coefficients for each layer.
• Constructing constraints to focus on full-time creators and live-stream content. For example: Their total revenue could not exceed 50% of total gmv.

Additional Information:

I've attached the minimal reproducible example here

Thank you for your support!