我有一個(gè)名為 Data 的類，如下所示：class Data: def __init__(self, ticker, comments, submissions): self.ticker = ticker self.comments = comments self.submissions = submissions其中tickerastring是comments類型對(duì)象的列表Comment，submissions是類型 objectf 的列表Submission。Comment并Submission擁有自己的領(lǐng)域?，F(xiàn)在我有一個(gè)類型的對(duì)象列表Data我想遍歷列表并獲取包含所有元素的 JSON 字符串并將其打印到文件中。我的代碼： json_string = json.dumps([ob.__dict__ for ob in data_list]) f = open("data.json", "w") f.write(json_string) f.close()這會(huì)引發(fā)以下類型的錯(cuò)誤：TypeError: Object of type Comment is not JSON serializable我不知道我在這里做錯(cuò)了什么，有人知道嗎？編輯：評(píng)論類：class Comment:def __init__(self, author_name, body, ups): self.author_name = author_name self.body = body self.ups = ups所有字段都是字符串/整數(shù)
2 回答
慕姐8265434
TA貢獻(xiàn)1813條經(jīng)驗(yàn) 獲得超2個(gè)贊
使用default=lambda x: x.__dict__應(yīng)該可以幫助你。它會(huì)轉(zhuǎn)換任何不可序列化的對(duì)象，你不必修改很多以前的代碼
import json
# rest of your code
with open("file.json", "w+", encoding="utf-8") as file:
json.dump(datalist, file, default=lambda x: x.__dict__) #datalist is a list in my case
編輯 ：
這是我測(cè)試時(shí)的完整代碼：
import json
class Data:
def __init__(self, ticker="string", comment=[], submissions=[]):
self.ticker = ticker
self.comments = comments
self.submissions = submissions
class Comment:
def __init__(self, author_name="", body="", ups=1):
self.author_name = author_name
self.body = body
self.ups = ups
class Submission:
def __init__(self, author_name="", body="", ups=1):
self.author_name = author_name
self.body = body
self.ups = ups
comments = [Comment(ups=i) for i in range(10)]
submissions = [Submission(ups=2*i) for i in range(10)]
datalist = [Data(comment=comments, submissions=submissions) for i in range(5)]
with open("file.json", "w+", encoding="utf-8") as file:
json.dump(datalist, file, default=lambda x: x.__dict__)
蝴蝶刀刀
TA貢獻(xiàn)1801條經(jīng)驗(yàn) 獲得超8個(gè)贊
默認(rèn)情況下不能序列化類。所以要么你必須手動(dòng)序列化它，就像你處理Data類一樣，要么使用自定義的 json 編碼器。
手動(dòng)：
class Data:
...
def to_json(self):
res = self.__dict__
res['comments'] = self.comments.__dict__
return res
然而這個(gè)解決方案并不是很靈活，所以最好使用自定義的 JSON 編碼器，它將自動(dòng)處理它在序列化過(guò)程中遇到的所有對(duì)象：
# from top of my head something like this:
from json import JSONEncoder
class MyEncoder(JSONEncoder):
def default(self, o):
# handle instance of `Data` during json.dump
if isinstance(o, Data):
return o.__dict__
# handle instance of `Comment` during json.dump
if isinstance(o, Comment):
return o.__dict__
return super().default(o)
json.dumps(data_list, cls=MyEncoder) # custom encoder should handle it
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