How do I override file.write() in Python 3? -

The code below works on Python 2.6 but not on Python 3.x:

  old_file_write = File.write class file (): def write (self, d): if isinstance (d, types.bytes): self.buffer.write (d) Other: old_file_write (d) # ... something I can not change the code or f = open ("x") f.write ("...") f.write (b "...") sys.stdout.write (b "...") system Do not want to. Stdout.write ("...") print (b "...") print ("...")  

The problem is that the first line one in Python 3.x Error will occur:

  name error: name 'file' is not defined  

How can I do this in Python 3.x?

In fact, two years later, I am still looking for a solution that will work on both versions (2.5+, and 3.x).

For those, who are still wondering why I am looking for it, only to work with new versions of Python old code (other code, which sometimes you have not modified Can be able to create).

This is not about my code, that is how you can write some code that plays well with bad code):

I see two problems.

1: Your file class is not hereditary to any particular class. If I have interpreted the situation properly, then it should be a subclass of io.TextIowrapper .

2: In both Python 2.6 and 3.x, there is no element in type module (which will need to be imported in the first place) byte . Recommended method is to use only byte on your code.

Radon snippet:

  Import io, sys class file (io.TextIowrapper): Def Def (self, d, encoding = sys.getdefaultencoding ()): if isinstance (D, bytes): d = d.decode (encoding) super (). Type (D) old_stdout = sys.stdout # If you can also use it 'a', 'a +', 'w +', 'r +', etc. / Code>  
 Now it should use the  sys.stdout.write  in the output file you specify. (If you do not want to write to a disk on a disk, but instead want to type the default  sys.stdout  buffer, then  sys.stdout = file (sys.stdout.detach)) < / Code> will probably work.) 
 
 Note that, because Python 3.x does not have a  file  class, but 2.6 has  IO  module , You have to use one of the classes of the  io  module. My above code is just an example, and if you want it to be more flexible, then you have to work on it. That is, what type of file you are writing / what mode you are writing in, you probably want to use a different class in  io .