python - 在嵌套字典上使用 ast.literal_eval

Question

我正在使用 ast.literal_eval 将我从 json.loads() 收到的数据更改为 Python 字典；但是，如果我应该以一种完全不同的方式来解决这个问题 - 请随时指出这一点。

# Authentication
buf = StringIO.StringIO()
c = pycurl.Curl()
c.setopt(c.URL, "https://kippt.com/api/account")
c.setopt(c.WRITEFUNCTION, buf.write)
c.setopt(c.HTTPHEADER, header)
c.perform()

result = buf.getvalue()
buf.close()

print result

# Printing Output
data_string = json.dumps(result)
jsonload = json.loads(data_string)
jsondict = ast.literal_eval(jsonload)

目前它可以正常使用单行 JSON 返回，例如:

{“用户名”:“my_username”，“api_token”:“my_api_token”}

我可以通过以下方式正确获取值:

print jsondict['username']
print jsondict['api_token']

我遇到问题的部分是数据嵌套时，例如:

{"meta": {"next": null, "total_count": 6, "previous": null, "limit": 20, "offset": 0}, "objects": [{"rss_url": "https://kippt.com/feed/username_here/stuff_here/cool-stuff", "updated": "1339003710", "title": "Cool Stuff", "created": "1339001514", "slug": "cool-stuff", "id": 54533, "resource_uri": "/api/lists/54533/"}, {"rss_url": "https://kippt.com/feed/username_here/stuff_here/programming", "updated": "1339003479", "title": "Programming", "created": "1339001487", "slug": "programming", "id": 54532, "resource_uri": "/api/lists/54532/"}, {"rss_url": "https://kippt.com/feed/username_here/stuff_here/android", "updated": "1339003520", "title": "Android", "created": "1339000936", "slug": "android", "id": 54530, "resource_uri": "/api/lists/54530/"}, {"rss_url": "https://kippt.com/feed/username_here/stuff_here/chrome", "updated": "1339000931", "title": "Chrome", "created": "1339000412", "slug": "chrome", "id": 54529, "resource_uri": "/api/lists/54529/"}, {"rss_url": "https://kippt.com/feed/username_here/stuff_here/inbox", "updated": "1338946730", "title": "Inbox", "created": "1338945940", "slug": "inbox", "id": 54432, "resource_uri": "/api/lists/54432/"}, {"rss_url": "https://kippt.com/feed/username_here/stuff_here/read-later", "updated": "1338945940", "title": "Read Later", "created": "1338945940", "slug": "read-later", "id": 54433, "resource_uri": "/api/lists/54433/"}]}

当我使用相同的代码(/api/lists 的交换 URL)时，我在运行脚本时收到以下错误:

Traceback (most recent call last): File "kippt.py", line 48, in jsondict = ast.literal_eval(jsonload) File "/usr/local/lib/python2.7/ast.py", line 80, in literal_eval return _convert(node_or_string) File "/usr/local/lib/python2.7/ast.py", line 63, in _convert in zip(node.keys, node.values)) File "/usr/local/lib/python2.7/ast.py", line 62, in return dict((_convert(k), _convert(v)) for k, v File "/usr/local/lib/python2.7/ast.py", line 63, in _convert in zip(node.keys, node.values)) File "/usr/local/lib/python2.7/ast.py", line 62, in return dict((_convert(k), _convert(v)) for k, v File "/usr/local/lib/python2.7/ast.py", line 79, in _convert raise ValueError('malformed string') ValueError: malformed string

任何帮助将不胜感激。谢谢!

编辑 - 答案如下:

看起来我的第一个输入可能被解释为 Python 语法，这是我的错误所在，因为我在技术上没有以正确的方式开始。

我现在只想 json.loads() 我从 cURL 得到的结果，而不是做我以前做的那些古怪的事情。

例如:

buf = StringIO.StringIO()
c = pycurl.Curl()
c.setopt(c.URL, "https://kippt.com/api/lists")
c.setopt(c.WRITEFUNCTION, buf.write)
c.setopt(c.HTTPHEADER, header)
c.perform()

result = buf.getvalue()
buf.close()

print result

# Printing Output
jsonload = json.loads(result)
print jsonload['meta']['total_count'] # Gets the total_count item in the meta object.

Answer 1

ast.literal_eval 嵌套字典没有问题:

>>> ast.literal_eval("{'a': {'b':'c'}}")
{'a': {'b': 'c'}}

ast.literal_eval 正在破坏，因为数据实际上是 JSON……而且 JSON 不是有效的 Python。具体来说，null 不是有效的 Python 文字。

为什么不直接使用 json.loads() 来加载数据？