您需要使用
JSONEncoder
的子类,并代理
build_dict
函数。
from __future__ import (absolute_import, division, print_function,)
import collections
import json
mycollection = [1, 2, 3, 4]
def build_dict(_id):
d = dict()
d['my_' + str(_id)] = _id
return d
class SeqProxy(collections.Sequence):
def __init__(self, func, coll, *args, **kwargs):
super(SeqProxy, *args, **kwargs)
self.func = func
self.coll = coll
def __len__(self):
return len(self.coll)
def __getitem__(self, key):
return self.func(self.coll[key])
class JsonEncoderProxy(json.JSONEncoder):
def default(self, o):
try:
iterable = iter(o)
except TypeError:
pass
else:
return list(iterable)
return json.JSONEncoder.default(self, o)
jsonencoder = JsonEncoderProxy()
collproxy = SeqProxy(build_dict, mycollection)
for chunk in jsonencoder.iterencode(collproxy):
print(chunk)
输出:
[
{
"my_1"
:
1
}
,
{
"my_2"
:
2
}
,
{
"my_3"
:
3
}
,
{
"my_4"
:
4
}
]
要逐块读取它,您需要使用JSONDecoder
并将可调用的函数作为object_hook
传递。当您调用JSONDecoder.decode(json_string)
时,此钩子将被用于每个新解码的对象(您列表中的每个dict
)。