Question

I am using Python 2.6.5 and Django 1.3 .while running the below code i am getting the above error

if chart_list is not None:
    if isinstance(chart_list, (Chart, PivotChart)):
        chart_list = [chart_list]
    chart_list = [c.hcoptions for c in chart_list]
    render_to_list = [s.strip() for s in render_to.split(',')]
    for hco, render_to in izip_longest(chart_list, render_to_list):
        if render_to:
            hco['chart']['renderTo'] = render_to
    embed_script = (embed_script % (simplejson.dumps(chart_list,skipkeys=False,   ensure_ascii=True, 
  check_circular=True, allow_nan=True, cls=None),
                                    CHART_LOADER_URL))
else:
    embed_script = embed_script %((), CHART_LOADER_URL)
return mark_safe(embed_script

Answer 1

Use of custom JSONEncoder should help

class DecimalEncoder(json.JSONEncoder):
    def default(self, o):
        if isinstance(o, decimal.Decimal):
            return float(o)
        super(DecimalEncoder, self).default(o)

# and then:
json.dumps(chart_list,..., cls=DecimalEncoder)

---

Updated

Updated according with Daniel’s comment (more DRY way)

from django.core.serializers.json import DjangoJSONEncoder
json.dumps(chart_list,..., cls=DjangoJSONEncoder)