python – Converting JSON String to Dictionary Not List

python – Converting JSON String to Dictionary Not List

Your JSON is an array with a single object inside, so when you read it in you get a list with a dictionary inside. You can access your dictionary by accessing item 0 in the list, as shown below:

json1_data = json.loads(json1_str)[0]

Now you can access the data stored in datapoints just as you were expecting:

datapoints = json1_data[datapoints]

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I have one more question if anyone can bite: I am trying to take the average of the first elements in these datapoints(i.e. datapoints[0][0]). Just to list them, I tried doing datapoints[0:5][0] but all I get is the first datapoint with both elements as opposed to wanting to get the first 5 datapoints containing only the first element. Is there a way to do this?

datapoints[0:5][0] doesnt do what youre expecting. datapoints[0:5] returns a new list slice containing just the first 5 elements, and then adding [0] on the end of it will take just the first element from that resulting list slice. What you need to use to get the result you want is a list comprehension:

[p[0] for p in datapoints[0:5]]

Heres a simple way to calculate the mean:

sum(p[0] for p in datapoints[0:5])/5. # Result is 35.8

If youre willing to install NumPy, then its even easier:

import numpy
json1_file = open(json1)
json1_str = json1_file.read()
json1_data = json.loads(json1_str)[0]
datapoints = numpy.array(json1_data[datapoints])
avg = datapoints[0:5,0].mean()
# avg is now 35.8

Using the , operator with the slicing syntax for NumPys arrays has the behavior you were originally expecting with the list slices.

Here is a simple snippet that reads in a json text file from a dictionary. Note that your json file must follow the json standard, so it has to have double quotes rather then single quotes.

Your JSON dump.txt File:

{test:1, test2:123}

Python Script:

import json
with open(/your/path/to/a/dict/dump.txt) as handle:
    dictdump = json.loads(handle.read())

python – Converting JSON String to Dictionary Not List

You can use the following:

import json

 with open(<yourFile>.json, r) as JSON:
       json_dict = json.load(JSON)

 # Now you can use it like dictionary
 # For example:

 print(json_dict[username])