ค้นหาวันที่ทำการทดสอบพร้อมผล "ผ่าน"
Find the dates of the tests taken with result "Pass".
df_Student_Tests_Taken = pd.DataFrame(columns=['date_test_taken', 'test_result'])
df_Student_Tests_Taken[df_Student_Tests_Taken['test_result'] == 'Pass']['date_test_taken']