common/tablib/format.py
import decimal
import json
import csv
from io import StringIO
from uuid import UUID
""" Tablib - formats
"""
from collections import OrderedDict
class Registry:
_formats = OrderedDict()
def register(self, key, format_or_path):
# Create Databook.<format> read or read/write properties
# Create Dataset.<format> read or read/write properties,
# and Dataset.get_<format>/set_<format> methods.
self._formats[key] = format_or_path
def register_builtins(self):
# Registration ordering matters for autodetection.
self.register('csv', CSVFormat())
self.register('json', JSONFormat())
def get_format(self, key):
if key not in self._formats:
raise Exception("OneForAll has no format '%s'." % key)
return self._formats[key]
registry = Registry()
def serialize_objects_handler(obj):
if isinstance(obj, (decimal.Decimal, UUID)):
return str(obj)
elif hasattr(obj, 'isoformat'):
return obj.isoformat()
else:
return obj
"""
Tablib - JSON Support
"""
class JSONFormat:
title = 'json'
extensions = ('json',)
@classmethod
def export_set(cls, dataset):
"""Returns JSON representation of Dataset."""
return json.dumps(dataset.dict, default=serialize_objects_handler)
""" Tablib - CSV Support.
"""
class CSVFormat:
title = 'csv'
extensions = ('csv',)
DEFAULT_DELIMITER = ','
@classmethod
def export_stream_set(cls, dataset, **kwargs):
"""Returns CSV representation of Dataset as file-like."""
stream = StringIO()
kwargs.setdefault('delimiter', cls.DEFAULT_DELIMITER)
_csv = csv.writer(stream, **kwargs)
for row in dataset._package(dicts=False):
_csv.writerow(row)
stream.seek(0)
return stream
@classmethod
def export_set(cls, dataset, **kwargs):
"""Returns CSV representation of Dataset."""
stream = cls.export_stream_set(dataset, **kwargs)
return stream.getvalue()