Question

尝试使用json.loads从外部Json文件导入字典，但是当我这样做时，我会收到一条错误消息。

import json
import random

winner = "None"
winners = 0

class player:
    def __init__(self, playernum):
        self.playernum = playernum
        self.score = random.randint(1,6)
        self.name = "foo"
player1 = player(1)
player2 = player(2)

if player1.score > player2.score:
    winner = player1.name
    winners = player1.score
elif player2.score > player1.score:
    winner = player2.name
    winners = player2.score

with open("highscores.txt", "a") as f:
  json.dump({winner : winners}, f)
f.close()

with open("highscores.txt", "r") as f:
  scores = json.load(f)
f.close()

print(scores)

Highscores.txt当前包含7个词典； {“丹尼尔”：71} {“乔纳森”：26} {“乔纳森”：58} {“丹尼尔”：90} {“乔纳森”：57} {“乔纳森”：80} {“乔纳森”：50} < / p>

它是否应该打印出文件，该文件应该由“ winner：winners”字典组成？相反，我收到此错误消息：

Traceback (most recent call last):
  File "C:/Users/jonat/AppData/Local/Programs/Python/Python36-32/neacode.py", line 119, in <module>
    scores = json.load(f)

  File "C:\Users\jonat\AppData\Local\Programs\Python\Python36-32\lib\json\__init__.py", line 299, in load
    parse_constant=parse_constant, object_pairs_hook=object_pairs_hook, **kw)
  File "C:\Users\jonat\AppData\Local\Programs\Python\Python36-32\lib\json\__init__.py", line 354, in loads
    return _default_decoder.decode(s)
  File "C:\Users\jonat\AppData\Local\Programs\Python\Python36-32\lib\json\decoder.py", line 342, in decode
    raise JSONDecodeError("Extra data", s, end)
json.decoder.JSONDecodeError: Extra data: line 1 column 15 (char 14)

为什么？

Answer 1

这是因为您要将字典附加到文件中，这是无效的json语法：

from io import StringIO
import json

s = '''{"a": 1}
{"b": 2}
{"c": 3}'''

fh = StringIO(s)
json.load(fh) # JSONDecodeError

此外，在以append（json.dump）模式打开的文件中使用'a'不会包含换行符，这会产生更糟糕的非json。为了解决这个问题，我将更改您附加到文件的方式：

with open('highscores.txt', 'a') as fh:
    obj = json.dumps({winner: winners})+'\n' # note the added newline here
    fh.write(obj)

这将允许您逐行读取文件：

with open('highscores.txt', 'r') as fh:
    scores = [json.loads(line.strip()) for line in fh]

print(scores)

另外，请注意，您不必致电fh.close()，因为with语句将为您解决这个问题

为什么无法加载此json数据？

1 个答案: