Re: Configuring an object via a dictionary

On 3/15/2024 5:30 AM, Loris Bennett via Python-list wrote:

Hi,
 I am initialising an object via the following:
      def __init__(self, config):
          self.connection = None
          self.source_name = config['source_name']
         self.server_host = config['server_host']
         self.server_port = config['server_port']
         self.user_base = config['user_base']
         self.user_identifier = config['user_identifier']
         self.group_base = config['group_base']
         self.group_identifier = config['group_identifier']
         self.owner_base = config['owner_base']
 However, some entries in the configuration might be missing.  What is
the best way of dealing with this?
 I could of course simply test each element of the dictionary before
trying to use.  I could also just write
         self.config = config
 but then addressing the elements will add more clutter to the code.
 However, with a view to asking forgiveness rather than
permission, is there some simple way just to assign the dictionary
elements which do in fact exist to self-variables?
 Or should I be doing this completely differently?

         self.source_name = config.get('source_name', default_value)
Or, if you like this kind of expression better,
         self.source_name = config.get('source_name') or default_value
.get() will return None if the key doesn't exist, or the default value if you specify one.