แสดงชื่อครูและจำนวนรายวิชาที่สอน
Show names of teachers and the number of courses they teach.
df_teacher = pd.DataFrame(columns=['Name', 'Teacher_ID'])
df_course_arrange = pd.DataFrame(columns=['Teacher_ID'])
df_course_arrange['Teacher_ID'].value_counts().rename('count').reset_index().merge(df_teacher, left_on='index', right_on='Teacher_ID')[['Name', 'count']]