Python编程语言的35个与众不同之处（语言特征和使用技巧）

...     print_data(group)
...
-----------
Group: hard
young               myope                   yes                     normal                  hard
young               hypermetrope            yes                     normal                  hard
pre-presbyopic      myope                   yes                     normal                  hard
presbyopic          myope                   yes                     normal                  hard
-----------
Group: none
young               myope                   no                      reduced                 none
young               myope                   yes                     reduced                 none
young               hypermetrope            no                      reduced                 none