Subclassing a Client

The biothings_client get_client function generates settings for a biothings client on-the-fly. However, sometimes a user may want to subclass an existing client. This can be accomplished by use of the instance parameter in the get_client function. Normally the get_client function returns an instantiated client object, however if instance is False, get_client returns the class itself (allowing it to be used as a parent class). See the following code snippet for an example:

In [1]: class CustomMyGeneClient(get_client('gene', instance=False)):
   ...:     def getgene(self, _id, fields=None, **kwargs):
   ...:         ''' overridden gene function '''
   ...:         r =  super(CustomMyGeneClient, self).getgene(_id=_id, fields=fields, **kwargs)
   ...:         r['custom-field'] = 'My custom field'
   ...:         return r
   ...:

In [2]: gene_client = CustomMyGeneClient()

In [3]: gene_client.getgene('1017', fields='symbol,name')
Out[3]:
{'_id': '1017',
 '_score': 13.409985,
 'custom-field': 'My custom field',
 'name': 'cyclin dependent kinase 2',
 'symbol': 'CDK2'}

Here we overrode the normal functioning of the getgene function in the MyGene client by adding a custom field to the result.