Assign variable value in JSON payload fomat - python

I am using python 3.6.3a. I would like to generate payload for each of the json records. I am using each variable to access the record. How to assign variable value (each in this case) in payload? I tried {each} and other methods but didn't work.
code snippet below.
json_records = [{"description":"<p>This is scenario1<\/p>","owner":"deb",
"priority":"high"},
{"description":"<p>This is scenario2<\/p>","owner":"deb",
"priority":"medium"}]
json_object = json.loads(json_records)
for each in json_object:
payload = """
{
"subject": "test",
"fieldValues": [
{each}
]
}
"""

There are two ways to approach this problem.
One way could be creating a dict() object and inserting keys as you wish, then json.dumps(object) to convert into string payload as in:
import json
json_records = [{"description":"This is scenario1</p>","owner":"deb","priority":"high"}
,{"description":"This is scenario2</p>","owner":"deb","priority":"medium"}]
for obj in json_records:
payload = dict()
payload['subject'] = 'test'
for key,value in obj.items():
payload['fieldName'] = {
key:value
}
print(json.dumps(payload))
#{"subject": "test", "fieldName": {"priority": "high"}}
#{"subject": "test", "fieldName": {"priority": "medium"}}
Second way is to create a textual payload from string as in, however if you need a valid JSON at the end, this would require a post-step of validation (something like try json.loads(payload) - So I'd just use the first method. I would use this method only if I have a specific requirements to generate the payload in a certain way.
import json
json_records = [{"description":"This is scenario1</p>","owner":"deb","priority":"high"}
,{"description":"This is scenario2</p>","owner":"deb","priority":"medium"}]
# json_object = json.loads(json_records) # json.loads works only on byte-like strings. your object is already in python in this case.
for obj in json_records:
payload = """
{
"subject": "test",
"fieldValues": [
%s
]
}
""" % (obj["priority"])
print(payload)
#{
# "subject": "test",
# "fieldValues": [
# high
# ]
# }
#
#
# {
# "subject": "test",
# "fieldValues": [
# medium
# ]
# }

You could make payload a Template string and use it to put the data in each JSON record into the format you want. Bracket {} characters have not special meaning in Templates, which is what makes using them easy.
Doing that will create a valid string representation of a dictionary containing everything. You can turn this into an actual Python dictionary data-structure using the ast.literal_eval() function, and then convert that into JSON string format — which I think is the final format you're after.
rom ast import literal_eval
import json
from string import Template
from textwrap import dedent
json_records = '''[{"description":"<p>This is scenario1<\/p>","owner":"deb",
"priority":"high"},
{"description":"<p>This is scenario2<\/p>","owner":"deb",
"priority":"medium"}]'''
json_object = json.loads(json_records)
payload = Template(dedent("""
{
"subject": "test",
"fieldValues": [
$each
]
}""")
)
for each in json_object:
obj = literal_eval(payload.substitute(dict(each=each)))
print(json.dumps(obj, indent=2))
Output:
{
"subject": "test",
"fieldValues": [
{
"description": "<p>This is scenario1</p>",
"owner": "deb",
"priority": "high"
}
]
}
{
"subject": "test",
"fieldValues": [
{
"description": "<p>This is scenario2</p>",
"owner": "deb",
"priority": "medium"
}
]
}

Related

Remove fields from a json array in Python

Currently I have a function returning json via jsonify.
[
{
"hostname": "bla",
"ipaddress": "192.168.1.10",
"subnetmask": "255.255.255.0",
"iloip": "192.168.1.11"
}
]
I want to keep it in json format, but I want to only show the fields I choose (i.e. reduce it). For this example, I want hostname and ipaddress.
Thanks
You can use dict comprehension:
json_input = '''
[
{
"hostname": "bla",
"ipaddress": "192.168.1.10",
"subnetmask": "255.255.255.0",
"iloip": "192.168.1.11"
}
]
'''
desired_keys = {'hostname', 'ipaddress'}
json_filtered = json.dumps([{ k:v for (k,v) in d.items() if k in desired_keys}
for d in json.loads(json_input)])
print(json_filtered)
output:
'[{"hostname": "bla", "ipaddress": "192.168.1.10"}]'
I belive what you want to achieve can be done with the code given below:
import json
data_json = '{"hostname": "bla","ipaddress": "192.168.1.10","subnetmask": "255.255.255.0","iloip": "192.168.1.11"}'
data = json.loads(data_json)
chosen_fields = ['hostname', 'ipaddress']
for field in chosen_fields:
print(f'{field}: {data[field]}')
Output:
hostname: bla
ipaddress: 192.168.1.10
Here what we do is we parse the stringified version of the json using the python's json module (i.e. json.loads(...)). Next decide on the fields we want to access (i.e. chosen_fields). Finally we iterate through the field we want to reach and get the corresponding values of the fields. This leaves the original json unmodified as you wished. Hope this helps.
Or else if you want these fields as a reduced json object:
import json
data_json = '{"hostname": "bla","ipaddress": "192.168.1.10","subnetmask": "255.255.255.0","iloip": "192.168.1.11"}'
data = json.loads(data_json)
chosen_fields = ['hostname', 'ipaddress']
reduced_json = "{"
for field in chosen_fields:
reduced_json += f'"{field}": "{data[field]}", '
reduced_json = list(reduced_json)
reduced_json[-2] = "}"
reduced_json = "".join(reduced_json)
reduced = json.loads(reduced_json)
for field in chosen_fields:
print(f'"{field}": "{reduced[field]}"')
Output:
"hostname": "bla"
"ipaddress": "192.168.1.10"
If I understand you correctly:
import json
response = [
{
"hostname": "bla",
"ipaddress": "192.168.1.10",
"subnetmask": "255.255.255.0",
"iloip": "192.168.1.11",
}
]
desired_keys = ["hostname", "ipaddress"]
new_response = json.dumps(
[{key: x[key] for key in desired_keys} for x in response]
)
And now you have a new_response - valid JSON, with which you can continue to work on

Parse JSON object with variable keys

I have to parse JSON objects which contains two keys which can be different in each object. In the example below it is the "path/to/file" and the accession "ecs2345.ms067".
I need to inspect both objects and evaluate the value of "ok" and "version".
All examples I found expect a defined key.
Parser is Python or Postgres jsonb. I am particularly interested if it is possible to use JSON path.
Thanks!
{
"path/to/file": [
{
"ecs2345.ms067": {
"error_type": "__prevalidation__",
"errors": [
"missing : origin_sample_ontology_curie"
],
"ok": false,
"version": "2.0"
}
},
{
"ecs2345.ms067": {
"errors": [],
"ok": true,
"version": "1.0"
}
}
]
}
Use json.loads to convert the whole thing to a dictionary and then iterate through the dictionary:
json_dict = json.loads(json_string)
for filename, file_data in json_dict.items():
for obj in file_data:
ok = obj["ok"]
version = obj["version"]
# do stuff with the variables.
# if you need the file name, it is filename variable.

Update json data with context in Python using jsonpath-ng

following Update json nodes in Python using jsonpath, would like to know how one might update the JSON data given a certain context.
So, say we pick the exact same JSON example:
{
"SchemeId": 10,
"nominations": [
{
"nominationId": 1
}
]
}
But this time, would like to double the value of the original value, hence some lambda function is needed which takes into account the current node value.
No need for lambdas; for example, to double SchemeId, something like this should work:
data = json.loads("""the json string above""")
jsonpath_expr = parse('$.SchemeId')
jsonpath_expr.find(data)
val = jsonpath_expr.find(data)[0].value
jsonpath_expr.update(data, val*2)
print(json.dumps(data, indent=2))
Output:
{
"SchemeId": 20,
"nominations": [
{
"nominationId": 1
}
]
}
Here is example with lambda expression:
import json
from jsonpath_ng import parse
settings = '''{
"choices": {
"atm": {
"cs": "Strom",
"en": "Tree"
},
"bar": {
"cs": "Dům",
"en": "House"
},
"sea": {
"cs": "Moře",
"en": "Sea"
}
}
}'''
json_data = json.loads(settings)
pattern = parse('$.choices.*')
def magic(f: dict, to_lang='cs'):
return f[to_lang]
pattern.update(json_data,
lambda data_field, data, field: data.update({field: magic(data[field])}))
json_data
returns
{
'choices': {
'atm': 'Strom',
'bar': 'Dům',
'sea': 'Moře'
}
}

How to change values in a json file using JsonPath in python

I have the following Json file: car_models.json
{
"name":"John",
"age":30,
"cars":
[
{
"car_model": "Mustang",
"car_brand": "Ford"
},
{
"car_model": "cx-5",
"car_brand": "Mazda"
}
]
}
I have another json file data_change.json, which contains details about the jsonpath and their values:
{
"testcase_ID": "test_1A",
"description": "Some description",
"request_change_data": [
{
"element_path": "$.cars.[0].car_model",
"element_value": "focus"
}
]
}
I want to read the data_change.json content, use the element_path from here, parse through car_models.json and update its value to the value from data_change.json.
As in, I want to use the jsonPath - $cars[0].car_model, parse through car_models.json, and change the value of car_model from Mustang to focus. So my updated car_models.json should be the following:
{
"name":"John",
"age":30,
"cars":
[
{
"car_model": "focus",
"car_brand": "Ford"
},
{
"car_model": "cx-5",
"car_brand": "Mazda"
}
]
}
How can I do this in python?
guessing that the Expected answer needs to have "focus" and not "ford"
The following should give you this:
import json
import re
with open('cars_model.json') as f:
cars_model = json.load(f)
with open('data_change.json') as f:
data_change = json.load(f)
for elements in data_change['request_change_data']:
element_path = elements['element_path']
#Reg ex to get you the number (as a string) between the square brackets
position_match = re.match(r"^.*\[(.*)\].*$", element_path)
position = int(position_match.group(1))
print position
# Split on "period" to get the thing to match
thing_to_change = element_path.split(".")[1]
print thing_to_change
value = elements['element_value']
print value
cars_model['cars'][0][thing_to_change] = value
print cars_model

Parsing a nested JSON keys and getting the values in a CSV format

I have a nested JSON data like this of about 5000 records.
{
"data": {
"attributes": [
{
"alert_type": "download",
"severity_level": "med",
"user": "10.1.1.16"
},
{
"alert_type": "download",
"severity_level": "low",
"user": "10.2.1.18"
}
]
}
}
Now , I need to parse this JSON and get only certain fields in a CSV format. Let's we would need alert_type & user in a CSV format.
I tried to parse this JSON dictionary:
>>> import json
>>> resp = '{"data":{"attributes":[{"alert_type":"download","severity_level":"med","user":"10.1.1.16"},{"alert_type":"download","severity_level":"low","user":"10.2.1.18"}]}}'
>>> user_dict = json.loads(resp)
>>> event_cnt = user_dict['data']['attributes']
>>> print event_cnt[0]['alert_type']
download
>>> print event_cnt[0]['user']
10.1.1.16
>>> print event_cnt[0]['alert_type'] + "," + event_cnt[0]['user']
download,10.1.1.16
>>>
How to get all the elements/values of a particular keys in a CSV format and in a single iteration ?
Output:
download,10.1.1.16
download,10.2.1.18
Simple list comprehension:
>>> jdict=json.loads(resp)
>>> ["{},{}".format(d["alert_type"],d["user"]) for d in jdict["data"]["attributes"]]
['download,10.1.1.16', 'download,10.2.1.18']
Which you can join for your desired output:
>>> li=["{},{}".format(d["alert_type"],d["user"]) for d in jdict["data"]["attributes"]]
>>> print '\n'.join(li)
download,10.1.1.16
download,10.2.1.18
Since {"data":{"attributes": is a list, you can loop over it and print the values for desired keys (d is the user dict):
for item in d['data']['attributes']:
print(item['alert_type'],',',item['user'], sep='')
You could make it somewhat data-driven like this:
import json
DESIRED_KEYS = 'alert_type', 'user'
resp = '''{ "data": {
"attributes": [
{
"alert_type": "download",
"severity_level": "med",
"user": "10.1.1.16"
},
{
"alert_type": "download",
"severity_level": "low",
"user": "10.2.1.18"
}
]
}
}
'''
user_dict = json.loads(resp)
for attribute in user_dict['data']['attributes']:
print(','.join(attribute[key] for key in DESIRED_KEYS))
To handle attributes that don't have all the keys, you could instead use this as the last line which will assign missing values a default value (such as a blank string as shown) instead of it causing an exception.
print(','.join(attribute.get(key, '') for key in DESIRED_KEYS))
Using jq, a one-line solution is straightforward:
$ jq -r '.data.attributes[] | [.alert_type, .user] | #csv' input.json
"download","10.1.1.16"
"download","10.2.1.18"
If you don't want the strings to be quoted, use join(",") instead of #csv

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