code: def process_symbol(writer, symbol):
      try:
          logger.info("Getting info for %s" % (symbol))
          url = "http://finance.yahoo.com/q/in?s=%s+Industry" % (symbol)
          htmlTree = lxml.html.parse(url)
  
          company = find_company(htmlTree, symbol)
          if not company:
              raise Exception("Company name not found")
  
          sector = find_sector(htmlTree)
          if not sector:
              sector = ""
              logger.warning("Sector not found")
  
          industry = find_industry(htmlTree)
          if not industry:
              industry = ""
              logger.warning("Industry not found")
  
          writer.addStock(symbol, company, sector, industry)
      except Exception as e:
          logger.error(str(e))
  
file_path: pyalgotrade/tools/symbols/get_merval_symbols.py
imports: import sys
  import pyalgotrade.logger
  import lxml.html
  import symbolsxml
label_desc: Use image node_id 4 for calling a global function with example usage: process_symbol(writer, symbol) without return types