[英]where can I find random() method in python's random module random.py?
[英]PYTHON: Error Message in random.py? Used to work, then it didn't, then it did, now it doesn't again. What's happening?
我已经学习python几个月了,通常我已经能够克服我面临的所有问题,但是现在我很茫然。 我正在编写一个名为“ Quizzer”的程序,该程序将用于根据给出的Python术语和答案列表生成随机问题。 我的主要问题与我一直在努力的gen_question函数有关。 我希望Python接收一个术语,并输出四个选择题答案:一个是实际的,三个是从所有可能答案中随机选择的。 我必须包括几项检查,以确保所选的随机答案不是真实答案,并且彼此不相同。
我终于让它今天开始工作,然后过一会儿我对其进行了测试。 我收到一条错误消息(稍后将显示)。 我撤消了一切,回到了以前的状态,但仍然收到相同的错误消息。 几个小时后,我回来了,我又得到了。 出于无奈,我重试了,它奏效了。 现在,它不再工作了。 拜托,任何人:这是怎么回事?
这是我的代码(我不知道有什么必要,所以我将整个内容包括在内):
#import random for generating
import random
#term and definition libraries
terms_ans ={'term1':'answer1','term2':'answer2','term3':'answer3','term4':'answer4','term5':'answer5','term6':'answer6','term7':'answer7','term8':'answer8','term9':'answer9','term10':'answer10','term11':'answer11','term12':'answer12','term13':'answer13','term14':'answer14','term15':'answer15','term16':'answer16','term17':'answer17','term18':'answer18','term19':'answer19','term20':'answer20'}
term_list = ['term1','term2','term3','term4','term5','term6','term7','term8','term9','term10','term11','term12','term13','term14','term15','term16','term17','term18','term19','term20']
answer_list = ['answer1','answer2','answer3','answer4','answer5','answer6','answer7','answer8','answer9','answer10','answer11','answer12','answer13','answer14','answer15','answer16','answer17','answer18','answer19','answer20']
#picks the test questions to ask
def gen_test(amount=len(term_list)):
found_starter = False
test_terms = []
while found_starter == False:
#pick a random starting point in the terms to see if it is suitable
start_point = random.randint(1, len(term_list))
if amount == len(term_list):
#if user inputs max amount of questions possible, just take the term list
test_terms = term_list
found_starter = True
elif len(term_list) - (start_point + amount) >= 0:
#if it is suitable, then append the terms to the test questions
for x in xrange(start_point,start_point+amount):
test_terms.append(term_list[x])
found_starter = True
else:
return test_terms
#scramble list
def list_scrambler(unscrambled_list):
test_terms=[]
countdown = len(unscrambled_list) + 1
for x in range(1, countdown):
transfer_var = random.randint(0,len(unscrambled_list)-1)
test_terms.append(unscrambled_list[transfer_var])
del unscrambled_list[transfer_var]
return test_terms
#ask user for amount of questions needed and get the list
test_terms = list_scrambler(gen_test(int(raw_input("How many questions on your test? (There are " + str(len(term_list)) + " questions in total.) "))))
def gen_question(picked_term, question_num=1, total_amount=len(test_terms)):
#print start of question
print
print "Question " + str(question_num) + " of " + str(total_amount) + ":"
print
print picked_term
print
#gather random multiple choice answers they must a) all be different and b) not be the answer
ans_1_acceptable = False
while ans_1_acceptable == False:
int_rand_ans_1 = random.randint(1, len(term_list)) - 1
if str(term_list[int_rand_ans_1]) != str(picked_term):
#Term accepted; send to output
ans_1_acceptable = True
ans_2_acceptable = False
while ans_2_acceptable == False:
int_rand_ans_2 = random.randint(1, len(term_list)) - 1
if int_rand_ans_2 != int_rand_ans_1 and str(term_list[int_rand_ans_2]) != str(picked_term):
ans_2_acceptable = True
ans_3_acceptable = False
while ans_3_acceptable == False:
int_rand_ans_3 = random.randint(1, len(term_list)) - 1
if int_rand_ans_3 != int_rand_ans_1 and int_rand_ans_3 != int_rand_ans_2 and str(term_list[int_rand_ans_3]) != str(picked_term):
ans_3_acceptable = True
#Decide if the correct answer is A, B, C, or D
correct_ans = random.randint(1,4)
#Print the options using the variables gathered above
if correct_ans != 1:
print "A) " + answer_list[int_rand_ans_1]
else:
print "A) " + terms_ans[picked_term]
if correct_ans != 2:
print "B) " + answer_list[int_rand_ans_2]
else:
print "B) " + terms_ans[picked_term]
if correct_ans != 3:
print "C) " + answer_list[int_rand_ans_3]
else:
print "C) " + terms_ans[picked_term]
if correct_ans == 1:
print "D) " + answer_list[int_rand_ans_1]
elif correct_ans == 2:
print "D) " + answer_list[int_rand_ans_2]
elif correct_ans == 3:
print "D) " + answer_list[int_rand_ans_3]
else:
print "D) " + terms_ans[picked_term]
print
现在,通常它会输出您期望的一切。 我还没有自动生成问题的功能,因此我必须输入以下内容:
gen_question('term1')
或我使用的任何术语。
这是我得到的输出:
How many questions on your test? (There are 20 questions in total.) 20
>>> gen_question('term1')
Question 1 of 20:
term1
Traceback (most recent call last):
File "<pyshell#0>", line 1, in <module>
gen_question('term1')
File "C:\Users\Owner\Desktop\LEARNING PYTHON\scripts\in progress\Quizzer.py", line 69, in gen_question
int_rand_ans_1 = random.randint(1, len(term_list)) - 1
File "C:\Users\Owner\Desktop\LEARNING PYTHON\python 2.7.5\lib\random.py", line 241, in randint
return self.randrange(a, b+1)
File "C:\Users\Owner\Desktop\LEARNING PYTHON\python 2.7.5\lib\random.py", line 217, in randrange
raise ValueError, "empty range for randrange() (%d,%d, %d)" % (istart, istop, width)
ValueError: empty range for randrange() (1,1, 0)
>>> gen_question('term8')
这就是让您:
term_list = [...]
是在文件的开头定义的,但是稍后在输入的数量为最大值时执行以下操作。
test_term = term_list
这不会创建数组的副本,而是会创建两个引用同一数组的变量。 因此,对test_term
任何进一步修改实际上都会反映在两个变量所引用的列表中。
而且由于您是在脚本的全局级别定义test_terms
,因此您在进行此调用时会对其进行NUKE
def list_scrambler(unscrambled_list):
test_terms=[]
countdown = len(unscrambled_list) + 1
for x in range(1, countdown):
transfer_var = random.randint(0,len(unscrambled_list)-1)
test_terms.append(unscrambled_list[transfer_var])
del unscrambled_list[transfer_var]
return test_terms
还要添加
匈牙利表示法是一个很大的禁忌,而python仍然是一种强类型语言。 如果您很难记录时间,请不要依赖变量名。 取而代之的是给自己一个IDE或使用表达他们正在做的事情的名称。
if something == false:
应该改写为
if not something
这是首选,但在打印需要浮动数据的文本时,您可以省去一些麻烦并编写
"D) {0}".format(somelist[index])
这会将变量填充到{0}中,并为您提供了一些格式设置上下文,并避免了您必须str()
一个对象。
同样,全球人士通常被认为是一件坏事,值得商de。 像C语言中的全局变量一样,有时它们有明确的目的,但是在大多数情况下,它们会隐藏错误并使问题难以跟踪。 同样,有时您的变量声明会遮盖全局变量,而其他变量声明(如您所见)会让您搞砸。
好吧,很明显randint()
正在抱怨,因为term_list
为空,对吗? 然后
random.randint(1, len(term_list))
是
random.randint(1, 0)
randint
被困住了。 那么为什么 term_list
空? 这是因为此语句:
test_terms = list_scrambler(gen_test(int(raw_input("How many questions on your test? (There are " + str(len(term_list)) + " questions in total.) "))))
销毁term_list
,这可能是;-)所不希望的。
很难遵循代码来跟踪发生这种情况的原因。 基本问题是gen_test
可以设置
test_terms = term_list
然后最终返回term_list
的名义下test_terms
。 然后term_list
在list_scrambler
的开头仍然是完整的,但是在list_scrambler
结束时为空。 该
del unscrambled_list[transfer_var]
一次删除term_list
所有元素。
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