IOError中出现"IOError：[Errno 0] Error“错误

Question

我有一个应该附加到文件中的脚本，但它引发了一个错误，我不理解它，也不确定它是如何被触发的。

代码如下：

import re

num_words = "four kiddiewinks|four children|four kids"
words_list = num_words.split('|')

def append_2synonym(words_list, num_words):
    with open('test2 words.txt', 'a+') as f:
        read_f = f.read()
        patt = r'^' + words_list[0] + '\|'
        result = re.search(patt, read_f, re.MULTILINE)
        if result == None:
            f.write("\n" + num_words)
        else:
            print "\nNo match found in '2 words.txt' file"

append_2synonym(words_list, num_words)

下面是'test2 words.txt‘文件的内容：

five kiddiewinks|five kids|five children
mobile phone|cell phone|cellular phone
stinky cheese|smelly cheese

下面是我得到的完整错误：

Traceback (most recent call last):
  File "D:\Magic Briefcase\My Python Scripts\Spin Scripts\synonyms\testing2.py", line 16, in <module>
    append_2synonym(words_list, num_words)
  File "D:\Magic Briefcase\My Python Scripts\Spin Scripts\synonyms\testing2.py", line 12, in append_2synonym
    f.write("\n" + num_words)
IOError: [Errno 0] Error
[Finished in 0.1s with exit code 1]

Answer 1

引用Python file operations的回答，当在Windows上进行读写切换时，必须有一个中间的fflush、fsetpos、fseek或rewind操作。

以下是一个可能的修复方法：

import re

num_words = "four kiddiewinks|four children|four kids"
words_list = num_words.split('|')

def append_2synonym(words_list, num_words):
    with open('test2 words.txt', 'a+') as f:
        read_f = f.read()
        patt = r'^' + words_list[0] + '\|'
        result = re.search(patt, read_f, re.MULTILINE)
        if result == None:
            f.seek(0,2) # change is here !!
            f.write("\n" + num_words)
        else:
            print "\nNo match found in '2 words.txt' file"

append_2synonym(words_list, num_words)

在f.seek(0,2)中，2是from_what参数。from_what值0从文件的开头开始测量，1使用当前文件位置，2使用文件结尾作为参考点。可以省略from_what并默认为0，使用文件的开头作为参考点。