As computing technologies continue to have a greater impact on daily life, it becomes increasingly important for the K-12 education system to prepare students for the computerized world. In this paper, we present the curriculum design, implementation, and results from a one-trimester introductory Python course that is mandatory for all 8th graders in our school district. This course is a crucial component of the K-12 computational thinking pathways we are developing at our school district, which take students from block-based programming and computational thinking (elementary school) to text-based programming and applications of computer science (high school). Our mandatory 8th grade course serves as a bridge between these two components. We present qualitative results that highlight the challenges that arose from teaching a course for all students -- not just those with a prior interest in computing -- and how the instructor overcame those challenges. We also present quantitative results that demonstrate the course's positive impact on students' attitudes towards computer science, their intent to re-engage with computer science in the future, and the gender gap with regards to confidence in computer science.