strange behaviour of str()

[Fredrik Lundh]

Juho Vuori wrote:

> str(u'lää') raises UnicodeEncodeError

> Is this behaviour sane? Possibly, but not documented at all.

str() on a Unicode string attempts to convert the string to an 8-bit
string using Python's default encoding, which is ASCII.  "ä" is not
an ASCII character.

if this problem appears in a 3rd party program, that program has
not been properly internationalized.

> Somehow you'd expect str() to never fail.

except for id() and type(), virtually all builtins can fail.  If you want
to convert something to a string no matter what it contains, repr() is
a better choice.  If you want to convert Unicode strings to a given
byte encoding, you have to use the encode method.

</F>