property file/value file parser in python

ValueFileParser.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

import sys

class _ValueFileParserError(Exception):
  pass

class ValueFileParser:
  def __init__(self, path):
    self.convertor = lambda v,t : map(t,v) if type(v) is list else t(v)
    try:
      f = open(path)
      self.props = {}
      for p in f.readlines():
        # use non-comment lines. comment lines begin with a '#'
        if p[0] != '#':
          try:
            # isolate key-value pairs
            key,value = p.split('=', 1)
            # strip away any leading/training spaces
            key,value = key.strip(),value.strip()
            # handle inline comments
            end = value.find('#')
            value = value[:end] if end != -1 else value
            # handle list of values for a key
            value = value.split(';') if len(value.split(';')) > 1 else value
            # associate value with key
            self.props[key] = value
          except ValueError:
            # non key-value pair line obtained
            continue
    except IOError:
      raise
    except:
      raise _ValueFileParserError("Unable to parse property file")

  def get_value(self, key, type=str):
    return self.props[key] if type is str else self.convertor(self.props[key], type)