JSON formatting adding \ characters when I append file, but not to string in output

问题

I am using the following function to get json from the flickr API. The string it returns is a properly formatted chunk of JSON:

def get_photo_data(photo_id):
    para = {}
    para["photo_id"] = photo_id
    para["method"] = "flickr.photos.getInfo"
    para["format"] = "json"
    para["api_key"] = FLICKR_KEY
    request_data = params_unique_combination("https://api.flickr.com/services/rest/", para)

    if request_data in CACHE_DICTION:
        return CACHE_DICTION[request_data]
    else:
        response = requests.get("https://api.flickr.com/services/rest/", para)
        CACHE_DICTION[request_data] = response.text[14:-1]
        cache_file = open(CACHE_FNAME, 'w')
        cache_file.write(json.dumps(CACHE_DICTION))
        cache_file.close()
        return response.text[14:-1]

The issue I am having is that when I go to write the json to my cache file it keeps adding in backslashes, like this example:

"https://api.flickr.com/services/rest/format-json_method-flickr.photos.getInfo_photo_id-34869402493": "{\"photo\":{\"id\":\"34869402493\",\"secret\":\"56fcf0342c\",\"server\":\"4057\",\"farm\":5,\"dateuploaded\":\"1499030213\",\"isfavorite\":0,\"license\":\"0\",\"safety_level\":\"0\",\"rotation\":0,\"originalsecret\":\"c4d1d316ed\",\"originalformat\":\"jpg\",\"owner\":{\"nsid\":\"150544082@N05\",\"username\":\"ankitrana_\",\"realname\":\"Ankit Rana\",\"location\":\"Cincinnati, USA\",\"iconserver\":\"4236\",\"iconfarm\":5,\"path_alias\":\"ankitrana_\"},\"title\":{\"_content\":\"7\"},\"description\":{\"_content\":\"\"},\"visibility\":{\"ispublic\":1,\"isfriend\":0,\"isfamily\":0},\"dates\":{\"posted\":\"1499030213\",\"taken\":\"2017-06-19 13:43:38\",\"takengranularity\":\"0\",\"takenunknown\":\"0\",\"lastupdate\":\"1499041020\"},\"views\":\"41\",\"editability\":{\"cancomment\":0,\"canaddmeta\":0},\"publiceditability\":{\"cancomment\":1,\"canaddmeta\":0},\"usage\":{\"candownload\":1,\"canblog\":0,\"canprint\":0,\"canshare\":1},\"comments\":{\"_content\":\"0\"},\"notes\":{\"note\":[]},\"people\":{\"haspeople\":0},\"tags\":{\"tag\":[{\"id\":\"150538742-34869402493-5630\",\"author\":\"150544082@N05\",\"authorname\":\"ankitrana_\",\"raw\":\"cincinnati\",\"_content\":\"cincinnati\",\"machine_tag\":0},{\"id\":\"150538742-34869402493-226\",\"author\":\"150544082@N05\",\"authorname\":\"ankitrana_\",\"raw\":\"ohio\",\"_content\":\"ohio\",\"machine_tag\":false}, ... etc., etc.}

How can I store the JSON to the existing file without these additional \ characters, as it is represented when I print the string?

回答1:

use your_string.decode('string_escape') to unescape \" to "

update:

your string escaped because json.dumps(), it convert object to string and later you can read it using json.loads(), the result are unescaped.

you can save it without slash using str()

cache_file.write(str(CACHE_DICTION))
# {'myparam' :'"162000","photo":...'

but the problem it save to file with single quotes, it not valid json and not compatible with json.loads()

my suggestion keep your code as above, except you want to store it to file CACHE_FNAME.json

cache_file = open(CACHE_FNAME, 'w')
cache_file.write(response.text)
cache_file.close()
# {"photos":{"page":1,"pages":6478,..}

回答2:

You could try replacing the "\" with the str.replace function in python

Add the code after the following line

cache_file = open(CACHE_FNAME, 'w')

json_item = str(json.dumps(CACHE_DICTION))
json_item.replace("\", "")

and change this line

cache_file.write(json.dumps(CACHE_DICTION))

cache_file.write(json_item)

let me know if this works for you

回答3:

just replace \ with a whitespace. I did the same thing while i was working with JSON.

json_new = json.replace('\\', '')

来源：https://stackoverflow.com/questions/45534383/json-formatting-adding-characters-when-i-append-file-but-not-to-string-in-out

标签

python

json

formatting

append

flickr