Short confusing example with unicode, print, and __str__

[Gary Herron]

Gerard Brunick wrote:
> I really don't understand the following behavior:
>
>  >>> class C(object):
> ...     def __init__(self, s): self.s = s
> ...     def __str__(self): return self.s
> ...
>  >>> cafe = unicode("Caf\xe9", "Latin-1")
>  >>> c = C(cafe)
>  >>> print "Print using c.s:", c.s
> Print using c.s: Café
>  >>> print "Print using just c:", c
> Print using just c: Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> UnicodeEncodeError: 'ascii' codec can't encode character u'\xe9' in 
> position 3: ordinal not in range(128)
>  >>> str(c)
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> UnicodeEncodeError: 'ascii' codec can't encode character u'\xe9' in 
> position 3: ordinal not in range(128)
>
> Why would "print c.s" work but the other two cases throw an exception?
> Any help understanding this would be greatly appreciated.
>
> Thanks in advance,
> Gerard
>   
It's the difference between how __str__ and __repr__  act on strings.

Here's s simpler example

 >>> d=unicode("Caf\xe9", "Latin-1")
 >>> repr(d)
"u'Caf\\xe9'"
 >>> str(d)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeEncodeError: 'ascii' codec can't encode character u'\xe9' in 
position 3: ordinal not in range(128)

Gary Herron