换行会在扫描字符串文字时导致SyntaxError：EOL

Question

An ipad application sends this json to me and I read it by request.POST.get and then pars it by ast.literal_eval

u'[\n {\n "type" : 2,\n "dateCreated" : "Wed, 24 Apr 2013 17:20:50 0100",\n "dateStart" : "Wed, 24 Apr 2013 18:00:00 0100",\n "appointmentId" : 0,\n "withP" : [\n\n ],\n "seenTime" : null,\n "ofCWithId" : 2,\n "ofClientWithId" : 68,\n "dateEnd" : "Wed, 24 Apr 2013 19:00:00 0100",\n "comments" : "Test test test\n.\n( ) \'\' test \'\' \' test \'\n",\n "inLocation" : null,\n ...bla bla bla...]'

I get this error:

    'comments' : 'Test test test
                               ^
SyntaxError: EOL while scanning string literal

I can understand that newline character is the problem but I don't know how to solve it. I'm using django 1.4.2 python 2.7.3

I really appreciate your help

Answer 1

Try to add \\'\\'\\' at the beginning of the string and at the end.

Like this:

u'\'\'\'[\n ... bla bla bla...]\'\'\''

Answer 2

You shouldn't use ast.literal_eval to read JSON. For reading JSON there is a separate module called json .

Load JSON data using it:

import json
data = """{"type":null,"dateCreated":"Wed, 24 Apr 2013 17:20:50 0100"}"""
json_data = json.loads(data)

ast.literal_eval was made to evaluate Python code that is represented as a string. It wasn't designed to work with JSON data. null in JSON is None in Python Dictionary, as an example of a difference.

Another reason you get an error is because JSON you try to parse is invalid . It looks like there's a server side problem or there is a problem with the way you get your JSON data from the server.

Newline symbols ( \\n ) should be escaped within a string. Also, ' shouldn't be escaped, according to JSON specs . Alternatively, you can use strict=False argument with json.loads to allow control characters inside strings.

Valid JSON from your example would look like this:

{
    "type": 2,
    "dateCreated": "Wed, 24 Apr 2013 17:20:50 0100",
    "dateStart": "Wed, 24 Apr 2013 18:00:00 0100",
    "appointmentId": 0,
    "withP": ["\\n\\n"],
    "seenTime": null,
    "ofCWithId": 2,
    "ofClientWithId": 68,
    "dateEnd": "Wed, 24 Apr 2013 19:00:00 0100",
    "comments": "Test test test\\n.\\n( ) '' test '' ' test '\\n",
    "inLocation": null
}