code: def getproxies_environment():
      
      proxies = {}
      for name, value in os.environ.items():
          name = name.lower()
          if value and name[-6:] == '_proxy':
              proxies[name[:-6]] = value
      return proxies
docs: Return a dictionary of scheme -> proxy server URL mappings.
  
      Scan the environment for variables named <scheme>_proxy;
      this seems to be the standard convention.  If you need a
      different way, you can pass a proxies dictionary to the
      [Fancy]URLopener constructor.