【发布时间】：2012-08-19 19:20:41
【问题描述】：
我仍在努力完成多项选择测验计划。我快到了。只有几个错误仍然可以解决。该程序会记录您正确、错误的问题数量和当前百分比。但是，我的程序不会运行，因为最初，用户没有回答任何问题。因此，它们的正确率为 NULL %。我的代码如下：
import random
import sys
import os
import math
right_answer_total = float(0)
wrong_answer_total = float(0)
answer_total = float(right_answer_total + wrong_answer_total)
percentage = 100 * (float(right_answer_total) / float(answer_total))
word_drills = {'class': 'Tell Python to make a new kind of thing.',
'object': 'Two meanings: the most basic kind of thing, and any instance of some thing.',
'instance': 'What you get when you tell Python to create a class.',
'def': 'How you define a function inside a class.',
'self': 'Inside the functions in a class, self is a variable for the instance/object being accessed.',
'inheritance': 'The concept that one class can inherit traits from another class, much like you and your parents.',
'composition': 'The concept that a class can be composed of other classes as parts, much like how a car has wheels.',
'attribute': 'A property classes have that are from composition and are usually variables.',
'is-a': 'A phrase to say that something inherits from another, as in a Salmon *** Fish',
'has-a': 'A phrase to say that something is composed of other things or has a trait, as in a Salmon *** mouth.'}
def start():
# For loop that creates a list named keys. It grabs 3 random keys from the dictionary word_drills
keys = [x for x in random.sample(word_drills, 3)]
# User is presented with a question. A value from the previous randomly selected keys is selected as the 'question'
correctanswer = word_drills[random.choice(keys)]
print "Question: ", correctanswer
# Set the variables key1, key2, & key3 to the 3 keys in the list 'keys'
key1, key2, key3 = keys[0], keys[1], keys[2]
# User is presented with 3 choices.
print "\n\n(a)%s (b)%s (c)%s" % (key1, key2, key3)
a, b, c = word_drills[key1], word_drills[key2], word_drills[key3]
selection = raw_input("> ")
print selection
if selection == "a":
if a == correctanswer:
print "That's correct!"
answered_correctly()
else:
print "I'm sorry, that is incorrect..."
not_answered_correctly()
elif selection == "b":
if b == correctanswer:
print "That's correct!"
answered_correctly()
else:
print "I'm sorry, that is incorrect..."
not_answered_correctly()
elif selection == "c":
if c == correctanswer:
print "That's correct!"
answered_correctly()
else:
print "I'm sorry, that is incorrect..."
not_answered_correctly()
else:
print "That is not a valid selection."
exit(0)
def answered_correctly():
global right_answer_total
right_answer_total += 1
stat_tracking()
def not_answered_correctly():
global wrong_answer_total
wrong_answer_total += 1
stat_tracking()
def stat_tracking():
os.system('cls' if os.name=='nt' else 'clear')
print "-" * 37
print "| Stat Tracking |"
print "-" * 37
print "| Correct | Incorrect | Percentage |"
print "-" * 37
print "| %d | %d | %d %% |" % (right_answer_total, wrong_answer_total, percentage)
print "-" * 37
print "\n\n\n"
start()
stat_tracking()
我不确定是否有解决此问题的方法，或者我是否可能做错了。任何和所有的帮助将不胜感激。谢谢。
【问题讨论】：
-
我忍不住注意到你的字符串的一些内容。
def可以在课堂之外使用。self只是一个常规名称；在实例方法中，无论第一个参数是当前实例，无论它的名称是什么。如果函数是类方法、静态方法或根本不在类中，情况会有所不同。模块也可以有属性，严格来说（如果我理解正确的话），方法也存储为属性；它们恰好是可调用的，因此可以附加括号来评估它们。
标签： python python-2.7 division divide-by-zero