python04 變數和變數的命名

我的理解，變數和代數基本上是一個概念。

ex4.py

cars = 100space_in_a_car = 4.0drivers = 30passengers = 90cars_not_driven = cars - driverscars_driven = driverscarpool_capacity = cars_driven * space_in_a_caraverage_passengers_per_car = passengers / cars_drivenprint "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."

1-8行中的那些單詞就是變數，同時可以看到，用=號來給變數賦值

稍微改下代碼

space_in_a_car = 4drivers = 30passengers = 90cars_not_driven = cars - driverscars = 100cars_driven = driverscarpool_capacity = cars_driven * space_in_a_caraverage_passengers_per_car = passengers / cars_drivenprint "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."

然後運行一下：

從而猜測，變數如果未賦值是不能使用的

再改下代碼

cars space_in_a_car = 4drivers = 30passengers = 90cars_not_driven = cars - driverscars_driven = driverscarpool_capacity = cars_driven * space_in_a_caraverage_passengers_per_car = passengers / cars_drivenprint "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."

果然。

至於NameError前的的單詞 cars為什麼會顯示"鍩縞ars"，我也沒弄明白，有知道的可以告訴我。