Why these python print commands behave differently with Python 2 and Python 3

I noticed

$ python2 -c 'print("A"*20 + "\xef\xbe\xad\xde" + "A"*4)'
AAAAAAAAAAAAAAAAAAAAﾭ▒AAAA

and

$ python3 -c 'print("A"*20 + "\xef\xbe\xad\xde" + "A"*4)'
AAAAAAAAAAAAAAAAAAAAï¾­ÞAAAA

gives different output.

I'm expecting to have same string output with python3 as with python2

I tried to change from string to bytes using

$ python3 -c 'print(b"A"*20 + b"\xef\xbe\xad\xde" + b"A"*4)'
b'AAAAAAAAAAAAAAAAAAAA\xef\xbe\xad\xdeAAAA'

but b'AAAAAAAAAAAAAAAAAAAA\xef\xbe\xad\xdeAAAA' is not AAAAAAAAAAAAAAAAAAAAﾭ▒AAAA

ie when piped to another process it's different.

Any idea how I can use Python3 to have same output than with Python 2 ?

Python2 is sending the bytes directly to your console without interpretation. Python3 is using Unicode codepoints in the string instead of bytes, and uses UTF-8 encoding to write them out.

You can get the same results in Python2:

print("A"*20 + "\xef\xbe\xad\xde" + "A"*4).decode('mbcs').encode('utf-8')

An alternative is to use bytes objects (which would be the equivalent of Python 2 str), and to write to the standard out directly (to the raw buffer, not the text i/o wrapper:

>>> import sys
>>> sys.stdout
<_io.TextIOWrapper name='<stdout>' mode='w' encoding='utf-8'>
>>> sys.stdout.buffer
<_io.BufferedWriter name='<stdout>'>
>>> stdout_raw = sys.stdout.buffer
>>> data = b"A"*20 + b"\xef\xbe\xad\xde" + b"A"*4 # notice I'm using bytes literals
>>> stdout_raw.write(data)
AAAAAAAAAAAAAAAAAAAAﾭ�AAAA28