在同一迭代中读取和写入文件

Question

假设我有一个文件列表，我想遍历它，为每个文件读取它的内容，将内容发送到一个函数processContent()，然后将所有内容写回到文件。下面的代码是否是一个适当的方法来做到这一点？

for curfile in files: 
    with open(curfile, 'r+') as infile 
     content = infile.read() 
     processed_content = processContent(content) 
     infile.write(processed_content) 

换句话说，在相同的迭代中读写。

Answer 1

for curfile in files: 
    with open(curfile, 'r+') as infile: 
     content = infile.read() 
     processed_content = processContent(content) 
     infile.truncate(0) # truncate the file to 0 bytes 
     infile.seek(0)  # move the pointer to the start of the file 
     infile.write(processed_content) 

或者使用临时文件中写入新的内容，然后将其重命名为原始文件：

import os 
for curfile in files: 
    with open(curfile) as infile: 
     with open("temp_file", 'w') as outfile: 
      content = infile.read() 
      processed_content = processContent(content) 
      outfile.write(processed_content) 
    os.remove(curfile) # For windows only 
    os.rename("temp_file", curfile) 

如果你要处理的一行一次，然后尝试fileinput模块