# -*- coding: utf-8 -*-

from importlib import import_module

__author__ = 'nemo'

class Singleton(type):

def __init__(cls, name, bases, dict):

super(Singleton, cls).__init__(name, bases, dict)

cls.instance = None

def __call__(cls, *args, **kw):

if cls.instance is None:

cls.instance = super(Singleton, cls).__call__(*args, **kw)

return cls.instance

def get_mod_func(path):

try:

dot = path.rindex(':')

except ValueError:

try:

dot = path.rindex('.')

except ValueError:

return path, ''

return path[:dot], path[dot+1:]

def load_by_path(path):

mod_name, func_name = get_mod_func(path)

if func_name != '':

package = None

if path.startswith('.'):

package = __package__

return getattr(import_module(mod_name, package), func_name)