Unicode, stdout, and stderr

[wxjmfauth at gmail.com]

Le mardi 22 juillet 2014 08:18:08 UTC+2, Frank Millman a écrit :
> Hi all
> 
> 
> 
> This is not important, but I would appreciate it if someone could explain 
> 
> the following, run from cmd.exe on Windows Server 2003 -
> 
> 
> 
> C:\>python
> 
> Python 3.4.1 (v3.4.1:c0e311e010fc, May 18 2014, 10:38:22) [MSC v.1600 32 bit 
> 
> (In
> 
> tel)] on win32
> 
> Type "help", "copyright", "credits" or "license" for more information.
> 
> >>> x = '\u2119'
> 
> >>> x  # this uses stderr
> 
> '\u2119'
> 
> >>> print(x)  # this uses stdout
> 
> Traceback (most recent call last):
> 
>   File "<stdin>", line 1, in <module>
> 
>   File "C:\Python34\lib\encodings\cp437.py", line 19, in encode
> 
>     return codecs.charmap_encode(input,self.errors,encoding_map)[0]
> 
> UnicodeEncodeError: 'charmap' codec can't encode character '\u2119' in 
> 
> position
> 
> 0: character maps to <undefined>
> 
> >>>
> 
> 
> 
> It seems that there is a difference between writing to stdout and writing to 
> 
> stderr. My questions are -
> 
> 
> 
> 1. What is the difference?
> 
> 
> 
> 2. Is there an easy way to get stdout to behave the same as stderr?
> 
> 
> 
%%%%%%%%%%%

Again, from my "magic" interactive intepreter.

>>> x = 'a\u2119z'
>>> sys.stdout.encoding
'<unicode>'
>>> x
'aℙz'
>>> sys.stdout.encoding = 'cp437'
>>> print(x)
Traceback (most recent call last):
  File "<eta last command>", line 1, in <module>
  File "D:\jm\jmpy\eta\eta41beta1\etastdio.py", line 158, in write
    s = s.encode(self.pencoding).decode('cp1252')
  File "c:\python32\lib\encodings\cp437.py", line 12, in encode
    return codecs.charmap_encode(input,errors,encoding_map)
UnicodeEncodeError: 'charmap' codec can't encode character '\u2119' in position 1:
 character maps to <undefined>
>>> print(x.encode(sys.stdout.encoding, 'replace'))
'a?z'
>>> # voilà, no error

jmf