Question

该功能应该（A）将文件的内容存储到列表中，（B）检查列表的内容是否与另一个列表的内容相同。但是，当我运行该程序时，根本没有任何东西出现。好像这个函数不在我的代码中.....

while True:
    try:
        fileObject = open("studentAnswers.txt", "r")
        index = 0
        correctAnswers = ["B", "D", "A", "A", "C", "A", "B", "A", "C", "D", \
"B", "C", "D", "A", "D", "C", "C", "B", "D", "A"]
        studentAnswers = []
        fileObject.readlines()

        for line in fileObject:
            studentAnswers.insert(index, line)
            index += 1
        index = 0

        for element in studentAnswers:
            if element == correctAnswers[index]:
                print("Question #", index, "is correct!")
            else:
                print("Question #", index, "is incorrect.")
            index += 1
        fileObject.close()

    except ValueError:
        print("Error.")
        break
    else:
        break

Answer 1

删除该行：

fileObject.readlines()

因为发生的事情是文件的指针到达文件的末尾，当你试图在下一个for循环中迭代它时，它实际上里面没有任何数据。

考虑以下示例：

>>> import StringIO
>>> output = StringIO.StringIO('aaaa\nbbb\nccc')
>>> output.readlines()
['aaaa\n', 'bbb\n', 'ccc']
>>> output.tell()
12
>>> for line in output:
...   print line
... 
>>> 
>>> output.seek(0)
>>> for line in output:
...   print line
... 
aaaa

bbb

ccc
>>>

如果功能没有存在..（怪异）

1 个答案: