支持2.7的远程加载模块

笔记：

# coding:utf8
'''
python2.7 支持的远程导入器
'''

import sys
import imp
import urllib2

class UrlMetaFinder(object):
    def __init__(self, baseurl):
        self._baseurl = baseurl


    def find_module(self, fullname, path=None):
        if path is None:
            baseurl = self._baseurl
        else:
            # 不是原定义的url就直接返回不存在
            if not path.startswith(self._baseurl):
                return None
            baseurl = path

        try:
            loader = UrlMetaLoader(baseurl)
            loader.load_module(fullname)
            return loader
        except Exception:
            return None

class UrlMetaLoader(object):
    def __init__(self, baseurl):
        self.baseurl = baseurl

    def get_code(self, fullname):
        f = urllib2.urlopen(self.get_filename(fullname))
        # f = urllib2.urlencode(self.get_filename(fullname))
        return f.read()

    def load_module(self, fullname):
        code = self.get_code(fullname)
        mod = sys.modules.setdefault(fullname, imp.new_module(fullname))
        mod.__file__ = self.get_filename(fullname)
        mod.__loader__ = self
        mod.__package__ = fullname
        exec(code, mod.__dict__)
        return mod

    def get_data(self):
        pass
    
    def execute_module(self, module):
        pass

    def get_filename(self, fullname):
        return self.baseurl + fullname + '.py'

def install_meta(address):
    finder = UrlMetaFinder(address)
    sys.meta_path.append(finder)