Extracting JSON element

I have a JSON response from the website shown below. I want to print the 'value' and 'datetime' keys of data. I am not able to access these two elements in JSON response.

'value'

'datetime'

data

data= {"parameter_name":"Inst",
"parameter_code":"WL1","data":[
{"value":3.1289999485,"datetime":"2018-07-01T00:00:00+00:00"},
{"datetime":"2018-07-01T00:30:00+00:00","value":3.1859998703},
{"value":3.33099985123,"datetime":"2018-07-01T00:45:00+00:00"},
{"datetime":"2018-07-01T01:15:00+00:00","value":3.22300004959},
{"datetime":"2018-07-01T01:45:00+00:00","value":3.32299995422}]}


my code till now

for element in len(data['data']):
date = element['datetime']
value = element['value']

print value, date


I am getting error

for element in len(data['data']):
TypeError: string indices must be integers, not str


3 Answers
3

What you've shown as your JSON data is likely not the actual value of data. If you attempt to access the data like a Python dict, it raises TypeError: string indices must be integers, not str. Your JSON data probably looks like this (notice the quotes):

data

data

dict

TypeError: string indices must be integers, not str

data

# This is JSON, essentialy a string in the format of a Python dict.
data = """{
"parameter_name": "Inst",
"parameter_code": "WL1",
"data":[
{
"value":3.1289999485,
"datetime":"2018-07-01T00:00:00+00:00"
},
{
"datetime":"2018-07-01T00:30:00+00:00",
"value":3.1859998703
},
{
"value":3.33099985123,
"datetime":"2018-07-01T00:45:00+00:00"
},
{
"datetime":"2018-07-01T01:15:00+00:00",
"value":3.22300004959
},
{
"datetime":"2018-07-01T01:45:00+00:00",
"value":3.32299995422
}
]
}"""


Convert it into a Python dict by using the Python Standard Library json package:

dict

json

import json

# This converts the JSON string into a Python dict
data = json.loads(data)


You can access the data and it's 'data' key, then iterate over it (like you were doing):

data

for element in data['data']:
print(element['value'], element['datetime'])


You can try like this:

for element in data['data']:
date = element['datetime']
value = element['value']

print(date)
print(value)


Output:

3.1289999485
2018-07-01T00:00:00+00:00
3.1859998703
2018-07-01T00:30:00+00:00
3.33099985123
2018-07-01T00:45:00+00:00
3.22300004959
2018-07-01T01:15:00+00:00
3.32299995422
2018-07-01T01:45:00+00:00


Explanation:

If you want to iterate over the elements in the list,:

list

for element in data['data']


If you want to iterate over the list using by their index:

for index in range(len(data['data'])):


If you have a web responce in text format you would also have to decode it first. Check
https://docs.python.org/2/library/json.html (for python 2) or https://docs.python.org/3.7/library/json.html (for python 3) to see the documentation about the json library.
You have to:

json

import json
decodedData = json.loads(data)


and then loop over decodedData as you've done.

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