如何用python和beautifulsoup解析html表并写入csv

Question

I try to parse html page and fetch values for currencies and write to csv. I have following code:

#!/usr/bin/env python

import urllib2
from BeautifulSoup import BeautifulSoup

contenturl = "http://www.bank.gov.ua/control/en/curmetal/detail/currency?period=daily"
soup = BeautifulSoup(urllib2.urlopen(contenturl).read())

table = soup.find('div', attrs={'class': 'content'})

rows = table.findAll('tr')
for tr in rows:
    cols = tr.findAll('td')
    for td in cols:
        text = td.find(text=True) + ';'
        print text,
    print

The problem is, that I do not know, how to retrieve only values for currency. I tried some regexp like '^[0-9]{3}' - start with 3 digits but it doesn't work.

Answer 1

You'd be much better off picking out specific cells in the table. The td cells with the cell_c class contain data you are interested in, and the last one is always the currency exchange rate:

rows = table.findAll('tr')
for tr in rows:
    cols = tr.findAll('td')
    if 'cell_c' in cols[0]['class']:
        # currency row
        digital_code, letter_code, units, name, rate = [c.text for c in cols]
        print digital_code, letter_code, units, name, rate

With the data in separate variables, you can now turn the text to decimal numbers, store them in a database, whatever.