如何将Unicode dict转换为dict

Question

I am trying to convert :

datalist = [u"{gallery: 'gal1', smallimage: 'http://www.styleever.com/media/catalog/product/cache/1/small_image/445x370/17f82f742ffe127f42dca9de82fb58b1/2/_/2_12.jpg',largeimage: 'http://www.styleever.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/2/_/2_12.jpg'}",
 u"{gallery: 'gal1', smallimage: 'http://www.styleever.com/media/catalog/product/cache/1/small_image/445x370/17f82f742ffe127f42dca9de82fb58b1/3/_/3_13.jpg',largeimage: 'http://www.styleever.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/3/_/3_13.jpg'}",
 u"{gallery: 'gal1', smallimage: 'http://www.styleever.com/media/catalog/product/cache/1/small_image/445x370/17f82f742ffe127f42dca9de82fb58b1/5/_/5_3_1.jpg',largeimage: 'http://www.styleever.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/5/_/5_3_1.jpg'}",
 u"{gallery: 'gal1', smallimage: 'http://www.styleever.com/media/catalog/product/cache/1/small_image/445x370/17f82f742ffe127f42dca9de82fb58b1/1/_/1_22.jpg',largeimage: 'http://www.styleever.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/1/_/1_22.jpg'}",
 u"{gallery: 'gal1', smallimage: 'http://www.styleever.com/media/catalog/product/cache/1/small_image/445x370/17f82f742ffe127f42dca9de82fb58b1/4/_/4_7_1.jpg',largeimage: 'http://www.styleever.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/4/_/4_7_1.jpg'}"]

To list containing python dict. If i try to extract value using keyword i got this error:

for i in datalist:
    print i['smallimage']
   ....:     

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-20-686ea4feba66> in <module>()
      1 for i in datalist:
----> 2     print i['smallimage']
      3 

TypeError: string indices must be integers

How do i convert list containing Unicode Dict to Dict..

Answer 1

You could use the demjson module which has a non-strict mode that handles the data you have:

import demjson

for data in datalist:
    dct = demjson.decode(data)
    print dct['gallery'] # etc...

Answer 2

In this case, I'd hand-craft a regular expression to make these into something you can evaluate as Python:

import re
import ast
from functools import partial

keys = re.compile(r'(gallery|smallimage|largeimage)')
fix_keys = partial(keys.sub, r'"\1"')

for entry in datalist:
    entry = ast.literal_eval(fix_keys(entry))

Yes, this is limited; but it works for this set and is robust as long as the keys match. The regular expression is simple to maintain. Moreover, this doesn't use any external dependencies, it's all based on batteries already included.

Result:

>>> for entry in datalist:
...     print ast.literal_eval(fix_keys(entry))
... 
{'largeimage': 'http://www.styleever.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/2/_/2_12.jpg', 'gallery': 'gal1', 'smallimage': 'http://www.styleever.com/media/catalog/product/cache/1/small_image/445x370/17f82f742ffe127f42dca9de82fb58b1/2/_/2_12.jpg'}
{'largeimage': 'http://www.styleever.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/3/_/3_13.jpg', 'gallery': 'gal1', 'smallimage': 'http://www.styleever.com/media/catalog/product/cache/1/small_image/445x370/17f82f742ffe127f42dca9de82fb58b1/3/_/3_13.jpg'}
{'largeimage': 'http://www.styleever.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/5/_/5_3_1.jpg', 'gallery': 'gal1', 'smallimage': 'http://www.styleever.com/media/catalog/product/cache/1/small_image/445x370/17f82f742ffe127f42dca9de82fb58b1/5/_/5_3_1.jpg'}
{'largeimage': 'http://www.styleever.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/1/_/1_22.jpg', 'gallery': 'gal1', 'smallimage': 'http://www.styleever.com/media/catalog/product/cache/1/small_image/445x370/17f82f742ffe127f42dca9de82fb58b1/1/_/1_22.jpg'}
{'largeimage': 'http://www.styleever.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/4/_/4_7_1.jpg', 'gallery': 'gal1', 'smallimage': 'http://www.styleever.com/media/catalog/product/cache/1/small_image/445x370/17f82f742ffe127f42dca9de82fb58b1/4/_/4_7_1.jpg'}

Answer 3

Just as another thought, your list is properly formatted Yaml.

> yaml.load(u'{foo: "bar"}')['foo']
'bar'

And if you want to be really fancy and parse everything at once:

> data = yaml.load('['+','.join(datalist)+']')
> data[0]['smallimage']
'http://www.styleever.com/media/catalog/product/cache/1/small_image/445x370/17f82f742ffe127f42dca9de82fb58b1/2/_/2_12.jpg'
> data[3]['gallery']
'gal1'

Answer 4

If your dictionary keys were quoted, you could use json.loads to load the string.

import json
for i in datalist:
   print json.loads(i)['smallimage']

( ast.literal_eval would have worked too...)

however, as it is, this will work with an old-school eval :

>>> class Mdict(dict):
...     def __missing__(self,key):
...        return key
... 
>>> eval(datalist[0],Mdict(__builtins__=None))
{'largeimage': 'http://www.styleever.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/2/_/2_12.jpg', 'gallery': 'gal1', 'smallimage': 'http://www.styleever.com/media/catalog/product/cache/1/small_image/445x370/17f82f742ffe127f42dca9de82fb58b1/2/_/2_12.jpg'}

Note that this is probably vulnerable to injection attacks, so only use it if the string is from a trusted source.

---

Finally, for anyone wanting a short, although somewhat dense solution that uses only the standard library and isn't vulnerable to injection attacks... This little gem does the trick (assuming the dictionary keys are valid identifiers)!

import ast
class RewriteName(ast.NodeTransformer):
    def visit_Name(self,node):
        return ast.Str(s=node.id)

transformer = RewriteName()
for x in datalist:
    tree = ast.parse(x,mode='eval')
    transformer.visit(tree)
    print ast.literal_eval(tree)['smallimage']

Answer 5

Your datalist is a list of unicode strings.

You could use eval , except your keys are not properly quoted. what you can do is requote your keys on the fly with replace :

for i in datalist:
    my_dict = eval(i.replace("gallery", "'gallery'").replace("smallimage", "'smallimage'").replace("largeimage", "'largeimage'"))
    print my_dict["smallimage"]

Answer 6

I don't see why the need for all the extra things such as using re or json ...

fdict = {str(k): v for (k, v) in udict.items()}

Where udict is the dict that has unicode keys. Simply convert them to str . In your given data, you can simply...

datalist = [dict((str(k), v) for (k, v) in i.items()) for i in datalist]

Simple test:

>>> datalist = [{u'a':1,u'b':2},{u'a':1,u'b':2}]
[{u'a': 1, u'b': 2}, {u'a': 1, u'b': 2}]
>>> datalist = [dict((str(k), v) for (k, v) in i.items()) for i in datalist]
>>> datalist
[{'a': 1, 'b': 2}, {'a': 1, 'b': 2}]

No import re or import json . Simple and quick.