You don't dump a string but to a string.
d = {"foo": "bar"}
j = json.dumps(d)
print(j)
Output:
{"foo": "bar"}
It makes no sense to use a string as the argument of json.dumps which is expecting a dictionary or a list/tuple as the argument.
Serialize
objto a JSON formatted str using this conversion table.
{data} is not valid JSON. Check it at jsonlint.com
'{"foo": "bar"}', the way @Ajay is doing it.In [17]: d = {"foo": "bar"}
In [18]: j = json.dumps(d)
In [19]: j
Out[19]: '{"foo": "bar"}'
Now if you need your dictionary back instead of a string
In [37]: l=json.loads(j)
In [38]: l
Out[38]: {u'foo': u'bar'}
or alternatively
In [20]: import ast
In [22]: k=ast.literal_eval(j)
In [23]: k
Out[23]: {'foo': 'bar'}
json.loads?By string, I take that the string is a valid json string. json.dumps() does not work with a string directly. Use json.loads() to convert a string to dict and then json.dumps() to dump out:
import json
A = '{"name": "Smith", "age": "10"}'
B = json.loads(A)
type(B) # dict
print(json.dumps(B))
{"name": "Smith", "age": "10"}
Or simply:
print( json.dumps(json.loads(A)) or
print( json.dumps(json.loads(A), indent=4) for pretty print
