Parsing values from a JSON file?
I have this JSON in a file:
{
"maps": [
{
"id": "blabla",
"iscategorical": "0"
},
{
"id": "blabla",
"iscategorical": "0"
}
],
"masks": [
"id": "valore"
],
"om_points": "value",
"parameters": [
"id": "valore"
]
}
I wrote this script which prints all of the json text:
json_data=open(file_directory).read()
data = json.loads(json_data)
pprint(data)
How can I parse the file and extract single values?
I think what Ignacio is saying is that your JSON file is incorrect. You have []
when you should have {}
. []
are for lists, {}
are for dictionaries.
Here's how your JSON file should look, your JSON file wouldn't even load for me:
{
"maps": [
{
"id": "blabla",
"iscategorical": "0"
},
{
"id": "blabla",
"iscategorical": "0"
}
],
"masks": {
"id": "valore"
},
"om_points": "value",
"parameters": {
"id": "valore"
}
}
Then you can use your code:
import json
from pprint import pprint
with open('data.json') as f:
data = json.load(f)
pprint(data)
With data, you can now also find values like so:
data["maps"][0]["id"]
data["masks"]["id"]
data["om_points"]
Try those out and see if it starts to make sense.
Your data.json
should look like this:
{
"maps":[
{"id":"blabla","iscategorical":"0"},
{"id":"blabla","iscategorical":"0"}
],
"masks":
{"id":"valore"},
"om_points":"value",
"parameters":
{"id":"valore"}
}
Your code should be:
import json
from pprint import pprint
with open('data.json') as data_file:
data = json.load(data_file)
pprint(data)
Note that this only works in Python 2.6 and up, as it depends upon the with
-statement. In Python 2.5 use from __future__ import with_statement
, in Python <= 2.4, see Justin Peel's answer, which this answer is based upon.
You can now also access single values like this:
data["maps"][0]["id"] # will return 'blabla'
data["masks"]["id"] # will return 'valore'
data["om_points"] # will return 'value'
data = []
with codecs.open('d:output.txt','rU','utf-8') as f:
for line in f:
data.append(json.loads(line))
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