rails select data format

irb(main):015:0> puts User.last.attributes.to_yaml

id: 38
employee_number: '9900714'
name: 秦延凯
mobile: ''
password_digest: "$2a$10$H/Zb3HV3t6vubvVq1EPXEOQ8aGkqhBha7ZzZyBjotnnvMkTH2Vf5i"
created_at: 2017-05-11 06:30:35.018380000 Z
updated_at: 2017-05-11 06:30:35.018380000 Z
admin: false