Source code for lightmlrestapi.tools.json_helper
"""
Helpers about :epkg:`json`.
:githublink:`%|py|5`
"""
import pprint
import numpy
import ujson
[docs]class JsonError(ValueError):
"""
Raised when serialization to json does not work.
:githublink:`%|py|13`
"""
[docs] def __init__(self, obj, data=None):
msg = pprint.pformat(obj)
if len(msg) > 2000:
msg = msg[:2000] + "\n..."
msg2 = pprint.pformat(data)
if len(msg2) > 2000:
msg2 = msg2[:2000] + "\n..."
ValueError.__init__(
self, "Unable to serialize object of type '{}' into json.\n{}\n----\n{}".format(
type(obj), msg, msg2))
[docs]def json_dumps(obj):
"""
Dumps an object into :epkg:`json`.
:param X: object
:return: json
:githublink:`%|py|34`
"""
def _modify(o):
return dict(shape=o.shape, dtype=str(o.dtype),
data=o.tolist(), ___=1)
if isinstance(obj, numpy.ndarray):
obj = _modify(obj)
elif isinstance(obj, dict):
obj = {k: (_modify(v) if isinstance(v, numpy.ndarray) else v)
for k, v in obj.items()}
try:
return ujson.dumps(obj, reject_bytes=False)
except UnicodeDecodeError:
raise JsonError(obj)
[docs]def json_loads(jsdata):
"""
Loads an object from :epkg:`json`.
:param jsdata: json
:return: object
:githublink:`%|py|56`
"""
obj = ujson.loads(jsdata)
if isinstance(obj, dict):
if '___' in obj:
# numpy array
shape = obj['shape']
obj = numpy.array(obj['data'], dtype=obj['dtype'])
obj = obj.reshape(tuple(shape))
else:
up = {}
for k, v in obj.items():
if isinstance(v, dict) and '___' in v:
shape = v['shape']
v = numpy.array(v['data'], dtype=v['dtype'])
v = v.reshape(tuple(shape))
up[k] = v
obj.update(up)
return obj