Python: modify builtin print functionality

Question

I want to customize the print statement in Python for additional text. But with my approach, it seems that the Enter key is getting buffered in the input.

The program I used is:

class rename_print:
    def __init__(self, stdout):
        self.stdout = stdout     
    def write(self, text):
        self.stdout.write('###' + text)     
        self.stdout.flush()
    def close(self):
        self.stdout.close()

import sys

prints = rename_print(sys.stdout)
sys.stdout = prints
print 'abc'

The output I get is

###abc###

The output I expected is

###abc

What might be the reason of this? I doubt that input stream is getting buffered with the Enter key. How can I solve this issue?

Answer 1

I think what is happening is that print implicitly adds a newline. This extra print is also calling your redirected write function so you get another "###\n"

It's a bit hacky, but try this:

...

def write(self, text):
    if text!="\n":
       self.stdout.write('###' + text)

...