Question: I know that to convert a dictionary to/from a string, I use `json.loads` and `json.dumps`. However, those methods fail when given a string representing a list of dictionaries. For example, 

```
sample_entry = [
    {"type": "test", "topic": "obama", "interval": "daily"},
    {"type": "test", "topic": "biden", "interval": "immediate"},
]

```

Converting that to a string with `str()` gives us 

```
"[{'topic': 'obama', 'interval': 'daily', 'type': 'test'}, {'topic': 'biden', 'interval': 'immediate', 'type': 'test'}]"

```

Is there an easy way of converting this back to a list of dictionaries? `eval` does precisely what I want, but I'm concerned about running it on a user-supplied string. 

Is there another way of accomplishing this that will be robust in the face of varying list lengths and variable white space?

EDIT: While json.loads(json.dumps(sample\_entry)) does indeed work, json.loads(str(sample\_entry)) does not. The difference, it seems, is where single quotes and double quotes are used. The data source I'm receiving this string from is unlikely to be consistent in use of ' vs ", so I'd like to account for both.

Answer: 
You may use [`ast.literal_eval`](https://docs.python.org/2/library/ast.html#ast.literal_eval):

```
>>> import ast
>>> my_str = "[{'topic': 'obama', 'interval': 'daily', 'type': 'test'}, {'topic': 'biden', 'interval': 'immediate', 'type': 'test'}]"

>>> ast.literal_eval(my_str)
[{'interval': 'daily', 'type': 'test', 'topic': 'obama'}, {'interval': 'immediate', 'type': 'test', 'topic': 'biden'}]

```

As per the [`ast.literal_eval` document](https://docs.python.org/2/library/ast.html#ast.literal_eval), it:

> 
> Safely evaluate an expression node or a Unicode or Latin-1 encoded string containing a Python literal or container display. The string or node provided may only consist of the following Python literal structures: strings, numbers, tuples, lists, dicts, booleans, and None.
> 
> 
>
> 
> Converting that to a string with str() gives us...
> 
> 
> 

There's your problem right there. You shouldn't be using `str` to serialize data. There's no guarantee that the resulting string will be something that can be recovered back into the original object.

Instead of using `str()`, use `json.dumps`. I know you said you tried it and it didn't work, but it's quite robust when used on built-in objects, so I suspect you may have just accidentally made a typo. The example dict you give serializes perfectly:

```
>>> sample_entry = [
...     {"type": "test", "topic": "obama", "interval": "daily"},
...     {"type": "test", "topic": "biden", "interval": "immediate"},
... ]
>>>
>>> s = json.dumps(sample_entry)
>>> print(s)
[{"interval": "daily", "topic": "obama", "type": "test"}, {"interval": "immediate", "topic": "biden", "type": "test"}]
>>>
>>> d = json.loads(s)
>>> d
[{'interval': 'daily', 'topic': 'obama', 'type': 'test'}, {'interval': 'immediate', 'topic': 'biden', 'type': 'test'}]

```