cars = 100 space_in_a_car = 4.0 drivers = 30 passengers = 90 cars_not_driven = cars - drivers cars_driven = drivers carpool_capacity = cars_driven * space_in_a_car average_passengers_per_car = passengers / cars_driven print "There are", cars, "cars available."
print "There are only", drivers, "drivers available."
print "There will be", cars_not_driven, "empty cars today."
print "We can transport", carpool_capacity, "people today."
print "We have", passengers, "to carpool today."
print "We need to put about", average_passengers_per_car, "in each car."
起名规则很重要。
变量，首字母小写，其余大写。
函数，均小写，单词间加连线符。
Exercise 4: Variables And Names
原文：http://www.cnblogs.com/hluo/p/4039475.html