习题4-变量和命名

• python变量和命名练习程序
• 附加练习

python变量和命名练习程序

# -*-coding: utf-8 -*-
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 availabes."
print "There are only", drivers,"drivers availabe."
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"

运行结果

PS F:\python大师\习题> 
PS F:\python大师\习题> python .\ex4.py
There are 100 cars availabes.
There are only 30 drivers availabe.
There will be 70 empty cars today.
We can transport 120.0 People today.
We have 90 to carpool today
We need to put about 3 in each car

附件练习

When I wrote this program the first time I had a mistake, and Python told me about it like this:

Traceback (most recent call last):
  File "ex4.py", line 8, in <module>
    average_passengers_per_car = car_pool_capacity / passenger
NameError: name 'car_pool_capacity' is not defined

原因：变量未定义