code: def postal(self):
      if self.address:
          expression = r"([ABCEGHJKLMNPRSTVXY]{1}\d{1}[A-Z]{1}( *\d{1}[A-Z]{1}\d{1})?)"
          pattern = re.compile(expression)
          match = pattern.search(self.address.upper())
          if match:
              return match.group(0)
  
file_path: geocoder/geocoder/ottawa.py
imports: from __future__ import absolute_import
  import logging
  import re
  from geocoder.base import OneResult, MultipleResultsQuery
label_desc: Use image node_id 3 for calling the OttawaResult obj's underlying member method code with example usage: obj.postal() and returns: match