How to print first(national) char from unicode string encoded inutf-8?

[sniipe at gmail.com]

On 2 Wrz, 10:17, sni... at gmail.com wrote:
> On 2 Wrz, 06:05, "Mark Tolonen" <M8R-yft... at mailinator.com> wrote:
>
>
>
> > "Marco Bizzarri" <marco.bizza... at gmail.com> wrote in message
>
> >news:mailman.331.1220276398.3487.python-list at python.org...
>
> > > On Mon, Sep 1, 2008 at 3:25 PM,  <sni... at gmail.com> wrote:
>
> > >> When I do ${urllib.unquote(c.user.firstName)} without encoding to
> > >> latin-1 I got different chars than I will get: no Ùukasz but Å ukasz
> > >> --
> > >>http://mail.python.org/mailman/listinfo/python-list
>
> > > That's crazy. "string".encode('latin1') gives you a latin1 encoded
> > > string; latin1 is a single byte encoding, therefore taking the first
> > > byte should be no problem.
>
> > > Have you tried:
>
> > > urlib.unquote(c.user.firstName)[0].encode('latin1') or
>
> > > urlib.unquote(c.user.firstName)[0].encode('utf8')
>
> > > I'm assuming here that the urlib.unquote(c.user.firstName) returns an
> > > encodable string (which I'm absolutely not sure), but if it does, this
> > > should take the first 'character'.
>
> > The OP stated that the original string was "encoded in UTF-8 and
> > urllib.quote()", so after urllib.unquote the string is in UTF-8 format.
> > This must be decoded into a Unicode string before removing the first
> > character:
>
> >     urllib.unquote(c.user.firstName).decode('utf-8')[0]
>
> > The next problem is that the character in the OP's example string 'Ù' is not
> > present in the latin-1 encoding, but using utf-8 encoding demonstrates that
> > the full two-byte UTF-8 encoded character is collected:
>
> >     >>> import urllib
> >     >>> name = urllib.quote(u'Ùukasz'.encode('utf-8'))
> >     >>> name
> >     '%C5%81ukasz'
> >     >>> urllib.unquote(name).decode('utf-8')[0].encode('utf-8')
> >     '\xc5\x81'
>
> > -Mark
>
> @Mark, when I tried urllib.unquote(c.user.firstName).decode('utf-8')
> [0].encode('utf-8'), I received this message:
>
> >>  return render('/reports/create_report_step2.mako')
>
> Module pylons.templating:344 in render
> <<                                      **cache_args)
>         return pylons.buffet.render(template_name=template,
> fragment=fragment,
>                                     format=format, namespace=kargs,
> **cache_args)
>
>     >>  format=format, namespace=kargs, **cache_args)
> Module pylons.templating:229 in render
> <<          log.debug("Rendering template %s with engine %s",
> full_path, engine_name)
>             return engine_config['engine'].render(namespace,
> template=full_path,
>                 **options)>>  **options)
> Module mako.ext.turbogears:49 in render
> <<              info.update(self.extra_vars_func())
>
>             return template.render(**info)
>     >>  return template.render(**info)
> Module mako.template:114 in render
> <<          declared by this template's internal rendering method are
> also pulled from the given *args, **data
>             members.        members."""
>             return runtime._render(self, self.callable_, args, data)
>
>         def render_unicode(self, *args, **data):>>  return
> runtime._render(self, self.callable_, args, data)
> Module mako.runtime:287 in _render
> <<      context = Context(buf, **data)
>         context._with_template = template
>         _render_context(template, callable_, context, *args,
> **_kwargs_for_callable(callable_, data))
>         return context.pop_buffer().getvalue()>>
> _render_context(template, callable_, context, *args,
> **_kwargs_for_callable(callable_, data))
> Module mako.runtime:304 in _render_context
> <<          # if main render method, call from the base of the
> inheritance stack
>             (inherit, lclcontext) = _populate_self_namespace(context,
> tmpl)
>             _exec_template(inherit, lclcontext, args=args,
> kwargs=kwargs)
>         else:
>             # otherwise, call the actual rendering method specified>>
> _exec_template(inherit, lclcontext, args=args, kwargs=kwargs)
> Module mako.runtime:337 in _exec_template
> <<                  error_template.render_context(context,
> error=error)
>         else:
>             callable_(context, *args, **kwargs)>>  callable_(context,
> *args, **kwargs)
> Module _reports_create_report_step2_mako:57 in render_body
> <<
> context.write(filters.decode.utf8(urllib.unquote(str(c.period.end))))
>                 context.write(u' + ')
>
> context.write(filters.decode.utf8(urllib.unquote(c.user.firstName).decode('utf-8')
> [0].encode('utf-8')))
>
> context.write(filters.decode.utf8(urllib.unquote(str(c.user.secondName)
> [0:1])))
>                 context.write(u'</h3>\r\n        <input type="hidden"
> name="works[]" value="')>>
> context.write(filters.decode.utf8(urllib.unquote(c.user.firstName).decode('utf-8')
> [0].encode('utf-8')))
> Module encodings.utf_8:16 in decode
> <<
>     def decode(input, errors='strict'):
>         return codecs.utf_8_decode(input, errors, True)
>
>     class IncrementalEncoder(codecs.IncrementalEncoder):>>  return
> codecs.utf_8_decode(input, errors, True)
> <type 'exceptions.UnicodeEncodeError'>: 'ascii' codec can't encode
> characters in position 0-1: ordinal not in range(128)

ok, I resolved this problem $
{urllib.unquote(str(c.user.firstName)).decode('utf-8')[0]}

Could anyone explain me why this code works?