Why does the "".join(r) do this?

[Jim Hefferon]

Hello,

I'm getting an error join-ing strings and wonder if someone can
explain why the function is behaving this way?  If I .join in a string
that contains a high character then I get an ascii codec decoding
error.  (The code below illustrates.)  Why doesn't it just
concatenate?

I'm building up a web page by stuffing an array and then doing
"".join(r) at
the end.  I intend to later encode it as 'latin1', so I'd like it to
just concatenate.  While I can work around this error, the reason for
it escapes me.

Thanks,
Jim

================= program: try.py
#!/usr/bin/python2.3 -u
t="abc"+chr(174)+"def"
print(u"next: %s :there" % (t.decode('latin1'),))
print t
r=["x",'y',u'z']
r.append(t)
k="".join(r)
print k

================== command line (on my screen between the first abc
and def is
  a circle-R, while between the second two is a black oval with a
white
  question mark, in case anyone cares):
jim at joshua:~$ ./try.py
next: abc®def :there
abc�def
Traceback (most recent call last):
  File "./try.py", line 7, in ?
    k="".join(r)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xae in position
3: ordinal not in range(128)