## ~!/usr/bin/env python3

from urllib import request
import sys
import re

def ParseRST(result):
    p = re.compile('.*AC:\s+(.*?)#')
    m = p.match(result)
    ac = m.group(1)
    q = re.compile('.*UPCOUNT:\s+(.*?)#')
    n = q.match(result)
    upresnum = int(n.group(1))

    return(ac, upresnum)

def ReadPDBSWS(pdbcode, chain, resnum):
    url = 'http://www.bioinf.org.uk/servers/pdbsws/query.cgi?plain=1&qtype=pdb'
    url += '&id=' + pdbcode
    if ('&chain' != ''):
        url += '&chain=' + chain
    url += '&res=' + str(resnum)
    result = request.urlopen(url).read()
    result = str(result, encoding='utf-8')
    result = result.replace('\n', '#')

    if (result != ''):
        rst = ParseRST(result)
        return(rst)
    else:
        sys.stderr.write('Nothing was returned\n')
    return('')

## Main program ##
pdbcode = input('Enter the pdbcode: ')
chain = input('Enter the chain label (optional): ')
resnum =  input('Enter the residue number: ')

(ac, upresnum) = ReadPDBSWS(pdbcode, chain, resnum)

print('Accession:        ' + ac)
print('UniProt Resnum: ' + str(upresnum))