python: getting ValueError: I/O operation on closed file

Question

我的代码有问题。我正在尝试替换文件中的模式。首先，我在打开文件的数量上有一个错误，因为我忘记关闭我的文件。但是现在，我的代码中有 f.close() 并且出现以下错误：

ValueError: I/O operation on closed file.

在这里您可以找到我的部分代码。有人知道出了什么问题吗？

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import re
import shutil
from tempfile import mkstemp

infile = 'test_file.txt'
year  = int('2009')
month = int('1')
day   = int('10')

#################################################################################
def sed(pattern, replace, source):
    """
    Reads a source file and writes the destination file.
    In each line, replaces pattern with replace.
    Args:
        pattern (str): pattern to match (can be re.pattern)
        replace (str): replacement str
        source  (str): input filename
    """
    fin = open(source, 'r')
    fd, name = mkstemp()
    fout = open(name, 'w')
    for line in fin:
        out = re.sub(pattern, replace, line)
        fout.write(out)
    fin.close()
    fout.close()
    shutil.move(name, source) 

#################################################################################
def main():
    """
    Replace all year-month-days which have a possible wrong pattern
    """
    for i in range (6):
        for j in range (12):
            for k in range (22):
                Year = year + i; Month = month + j; Day = day + k
                pattern = '%s %s%s' %(Year, Month, Day)
                replace = '%s %s %s' %(Year, Month, Day)
                sed(pattern, replace, infile)

#################################################################################
if __name__ == "__main__":
    main()

###### END

非常感谢。

Answer 1

我认为问题在于您错误地使用了 sed 函数。您在 main 函数中打开要编辑的文件，然后在 sed 函数中再次打开（然后关闭）。

看起来您的 sed 函数应该用于整个文件，而不仅仅是一行。

如果您将 main 函数编辑成类似的东西，它应该可以工作（如果不能，请评论错误）：

def main():
    """
    Replace all year-month-days which have a possible wrong pattern
    """
    occurrences = 999 # arbitray number. If you know the exact number, you may want to edit this.
    for i in range (6):
        for j in range (12):
            for k in range (22):
                Year = year + i; Month = month + j; Day = day + k
                pattern = '%s %s%s' %(Year, Month, Day)
                replace = '%s %s %s' %(Year, Month, Day)
                sed(pattern, replace, infile, count=occurrences)

Answer 2

我将此作为另一个答案发布，因为它明显不同。

由于您的 sed 函数打开太多文件时出现问题，我尝试编写一些尽可能少打开文件的程序。而且，你说你要编辑的文件很大，所以我就避免直接读入内存了。

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import re

input_file = 'test_file.txt'
output_file = 'result_file.txt'

def main():
  pattern = r"(\d{4}) (\d{1,2})(\d{2})"
  replace = r"  "
  with open(input_file, "r") as inp:
    with open(output_file, "w") as oup:
        for line in inp:
          sub = re.sub(pattern, replace, line)
          oup.write(sub)

if __name__ == "__main__":
    main()

python: getting ValueError: I/O operation on closed file

python: getting ValueError: I/O operation on closed file

python

fclose

valueerror