people = 20
cats = 30
dogs = 15 if people < cats:
print "Too many cats! The world is doomed!" if people > cats:
print "Not many cats! The world is saved!" if people < dogs:
print "The world is drooled on!" if people > dogs:
print "The world is dry!" dogs += 5 if people >= dogs:
print "People are greater than or equal to dogs." if people <=dogs:
print "People are less than or equal to dogs." if people == dogs:
print "people are dogs."
dogs += 5 即 dogs = dogs + 5
此时dogs=20，同时满足三个条件，输出三句