The Statistical Python project was launched with support from a grant from the NSF, titled “POSE: Phase I: An open-source ecosystem for statistical Python.” We are now completing Phase I, which has centered on scoping activities to inform the transition into a sustainable open-source ecosystem. During this phase, we conducted interviews with stakeholders across the statistical and scientific Python communities, engaged with related domain-stack OSEs to learn from their experiences, and organized a workshop to gather input on community needs and technical directions.