下面我们学习if语句，输入下面的代码，确保能够正确运行。
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 people:
print “we should take the cars.”
elif cars < people:
print "we should not take the cars."
else:
print "we can't dicide."
if buses > cars:
print “that’s too many buses.”
elif buses < cars:
print "maybe we could take the buses."
else:
print "we still can't decide."
if people > buses:
print “alright, let’s just take the buses.”
else:
print “fine, let’s stay home then.”
运行结果
root@he-desktop:~/mystuff# python ex30.py
we should take the cars.
maybe we could take the buses.
alright, let’s just take the buses.