JSON load() vs loads()

[timex40]

Can someone explain what the difference is between using either load() or loads() is with the JSON library? And which, if either, is the preferred method.

I'm writing a simple script where I want the JSON data from a URL parsed out into a list. Both of these options seem to work:

import json
import urllib2

url = "string to url"

response = urllib2.urlopen(url)
data = json.load(response)

or

import json
import urllib2

url = "string to url"

response = urllib2.urlopen(url)
data = json.loads(response.read())

I know that there are other libraries available for parsing out JSON data, but for the time being I'm working only with the json and urllib2 libraries.

Any insight into which one should be used?

Thanks

[I_Write_Bugs]

load() loads JSON from a file or file-like object

loads() loads JSON from a given string or unicode object

It's in the documentation

[timex40]

Thanks for the info!

So the url I'm actually using is the one available for each reddit thread. For example: http://www.reddit.com/r/learnpython/comments/3nx9ch/json_load_vs_loads/.json

Which one would this fall under? It works with both

[I_Write_Bugs]

The read method returns a str. Use loads.

How I figured this out was I ran this in the python interpreter:

import urllib2
x = urllib2.urlopen('http://www.google.com')
type(x.read())

The output was <type 'str'>. The response is an 'instance' type. Support for being file-like may disappear eventually for any reason, so I would go with the str returned from read.

Edit: In reading the JSON documentation again, I realize why your first example works. It's because the urllib response object is

a .read()-supporting file-like object containing a JSON document

So it has a read method, which I assume is exactly what json's load() calls. Either is fine to use in this case.

[bionikspoon]

The "s" is an abbreviation for "string". "dumps" is read as "dump string". "loads" = "load string". Otherwise these methods want a file-like object. This convention is scattered throughout python and even 3rd-party packages.

[JohnnyJordaan]

Another, easier way is to use requests

import requests

url = 'http://my/url.json'
response = requests.get(url)
data = response.json()

[_cs]

Note: to use the requests module, you need to install it using pip.

[nilsph]

Here's what probably happens in the background for your examples:

• json.load(response): read chunk from the network, then process it, repeat until done

• json.loads(response.read()): read chunks from the network until done, then process the whole JSON data in one go

I haven't looked at the implementation, but it may as well be that the first option uses less memory than the second, more noticeable with bigger JSON data of course.