Convert a String representation of a Dictionary to a dictionary?

Question

How can I convert the str representation of a dict, such as the following string, into a dict?

s = \"{\'muffin\' : \'l         


        

Answer 1

Use json. the ast library consumes a lot of memory and and slower. I have a process that needs to read a text file of 156Mb. Ast with 5 minutes delay for the conversion dictionary json and 1 minutes using 60% less memory!

Answer 2

string = "{'server1':'value','server2':'value'}"

#Now removing { and }
s = string.replace("{" ,"")
finalstring = s.replace("}" , "")

#Splitting the string based on , we get key value pairs
list = finalstring.split(",")

dictionary ={}
for i in list:
    #Get Key Value pairs separately to store in dictionary
    keyvalue = i.split(":")

    #Replacing the single quotes in the leading.
    m= keyvalue[0].strip('\'')
    m = m.replace("\"", "")
    dictionary[m] = keyvalue[1].strip('"\'')

print dictionary

Answer 3

To OP's example:

s = "{'muffin' : 'lolz', 'foo' : 'kitty'}"

We can use Yaml to deal with this kind of non-standard json in string:

>>> import yaml
>>> s = "{'muffin' : 'lolz', 'foo' : 'kitty'}"
>>> s
"{'muffin' : 'lolz', 'foo' : 'kitty'}"
>>> yaml.load(s)
{'muffin': 'lolz', 'foo': 'kitty'}

Answer 4

If the string can always be trusted, you could use eval (or use literal_eval as suggested; it's safe no matter what the string is.) Otherwise you need a parser. A JSON parser (such as simplejson) would work if he only ever stores content that fits with the JSON scheme.

Answer 5

https://docs.python.org/3.8/library/json.html

JSON can solve this problem though its decoder wants double quotes around keys and values. If you don't mind a replace hack...

import json
s = "{'muffin' : 'lolz', 'foo' : 'kitty'}"
json_acceptable_string = s.replace("'", "\"")
d = json.loads(json_acceptable_string)
# d = {u'muffin': u'lolz', u'foo': u'kitty'}

NOTE that if you have single quotes as a part of your keys or values this will fail due to improper character replacement. This solution is only recommended if you have a strong aversion to the eval solution.

More about json single quote: jQuery.parseJSON throws “Invalid JSON” error due to escaped single quote in JSON

Answer 6

To summarize:

import ast, yaml, json, timeit

descs=['short string','long string']
strings=['{"809001":2,"848545":2,"565828":1}','{"2979":1,"30581":1,"7296":1,"127256":1,"18803":2,"41619":1,"41312":1,"16837":1,"7253":1,"70075":1,"3453":1,"4126":1,"23599":1,"11465":3,"19172":1,"4019":1,"4775":1,"64225":1,"3235":2,"15593":1,"7528":1,"176840":1,"40022":1,"152854":1,"9878":1,"16156":1,"6512":1,"4138":1,"11090":1,"12259":1,"4934":1,"65581":1,"9747":2,"18290":1,"107981":1,"459762":1,"23177":1,"23246":1,"3591":1,"3671":1,"5767":1,"3930":1,"89507":2,"19293":1,"92797":1,"32444":2,"70089":1,"46549":1,"30988":1,"4613":1,"14042":1,"26298":1,"222972":1,"2982":1,"3932":1,"11134":1,"3084":1,"6516":1,"486617":1,"14475":2,"2127":1,"51359":1,"2662":1,"4121":1,"53848":2,"552967":1,"204081":1,"5675":2,"32433":1,"92448":1}']
funcs=[json.loads,eval,ast.literal_eval,yaml.load]

for  desc,string in zip(descs,strings):
    print('***',desc,'***')
    print('')
    for  func in funcs:
        print(func.__module__+' '+func.__name__+':')
        %timeit func(string)        
    print('')

Results:

*** short string ***

json loads:
4.47 µs ± 33.4 ns per loop (mean ± std. dev. of 7 runs, 100000 loops each)
builtins eval:
24.1 µs ± 163 ns per loop (mean ± std. dev. of 7 runs, 10000 loops each)
ast literal_eval:
30.4 µs ± 299 ns per loop (mean ± std. dev. of 7 runs, 10000 loops each)
yaml load:
504 µs ± 1.29 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)

*** long string ***

json loads:
29.6 µs ± 230 ns per loop (mean ± std. dev. of 7 runs, 10000 loops each)
builtins eval:
219 µs ± 3.92 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)
ast literal_eval:
331 µs ± 1.89 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)
yaml load:
9.02 ms ± 92.2 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)

Conclusion: prefer json.loads