mechanize submit form character encoding problem

Question

I am trying to scrape http://www.nscb.gov.ph/ggi/database.asp, specifically all the tables you get from selecting the municipalities/provinces. I am using python with lxml.html and mechanize. my scraper works fine so far, however I get HTTP Error 500: Internal Server Error when submitting the municipality[19] "Peñarrubia, Abra". I suspect this is due to the character encoding. My guess is that the ene character (n with a tilde above) causes this problem. How can I fix this?

A working example of this part of my script is shown below. As I am just starting out in python (and often use snippets I find on SO), any further comments are greatly appreciated.

from BeautifulSoup import BeautifulSoup
import mechanize
import lxml.html
import csv



class PrettifyHandler(mechanize.BaseHandler):
    def http_response(self, request, response):
        if not hasattr(response, "seek"):
            response = mechanize.response_seek_wrapper(response)
        # only use BeautifulSoup if response is html
        if response.info().dict.has_key('content-type') and ('html' in response.info().dict['content-type']):
            soup = BeautifulSoup(response.get_data())
            response.set_data(soup.prettify())
        return response

site = "http://www.nscb.gov.ph/ggi/database.asp"

output_mun = csv.writer(open(r'output-municipalities.csv','wb'))
output_prov = csv.writer(open(r'output-provinces.csv','wb'))

br = mechanize.Browser()
br.add_handler(PrettifyHandler())


# gets municipality stats
response = br.open(site)
br.select_form(name="form2")
muns = br.find_control("strMunicipality2", type="select").items
# municipality #19 is not working, those before do
for pos, item in enumerate(muns[19:]): 
    br.select_form(name="form2")
    br["strMunicipality2"] = [item.name]
    print pos, item.name 
    response = br.submit(id="button2", type="submit")
    html = response.read()
    root = lxml.html.fromstring(html)
    table = root.xpath('//table')[1]
    data = [
               [td.text_content().strip() for td in row.findall("td")] 
               for row in table.findall("tr")
           ]
    print data, "\n"
    for row in data[2:]:
        if row: 
            row.append(item.name)
            output_mun.writerow([s.encode('utf8') if type(s) is unicode else s for s in row])
    response = br.open(site) #go back button not working

# provinces follow here

Thank you very much!

edit: to be specific, the error occur on this line

response = br.submit(id="button2", type="submit")

Answer 1

quick and dirty hack:

def _pairs(self):
    return [(k, v.decode('utf-8').encode('latin-1')) for (i, k, v, c_i) in self._pairs_and_controls()]

from mechanize import HTMLForm
HTMLForm._pairs = _pairs

or something less invasive (I think there are no other solutions because the class Item protects 'name' field)

item.__dict__['name'] = item.name.decode('utf-8').encode('latin-1')

before

br["strMunicipality2"] = [item.name]