Exclude empty/null values from JSON serialization

Question

I am serializing multiple nested dictionaries to JSON using Python with simplejson.

Is there any way to automatically exclude empty/null values?

For example, serialize this:

 {      "dict1" : {      "key1" : "value1",      "key2" : None      }  } 

to

 {      "dict1" : {      "key1" : "value1"      }  } 

When using Jackson with Java you can use Inclusion.NON_NULL to do this. Is there a simplejson equivalent?

Answer 1

def del_none(d):     """     Delete keys with the value ``None`` in a dictionary, recursively.      This alters the input so you may wish to ``copy`` the dict first.     """     # For Python 3, write `list(d.items())`; `d.items()` won’t work     # For Python 2, write `d.items()`; `d.iteritems()` won’t work     for key, value in list(d.items()):         if value is None:             del d[key]         elif isinstance(value, dict):             del_none(value)     return d  # For convenience 

Sample usage:

>>> mydict = {'dict1': {'key1': 'value1', 'key2': None}} >>> print(del_none(mydict.copy())) {'dict1': {'key1': 'value1'}} 

Then you can feed that to json.