Foreach loop in Python to extract value from array in json response

I've got this json response:

{
"properties": {
"basic": {
"bandwidth_class": "",
"failure_pool": "",
"max_connection_attempts": 0,
"max_idle_connections_pernode": 50,
"max_timed_out_connection_attempts": 2,
"monitors": [
"Simple HTTP"
],
"node_close_with_rst": false,
"node_connection_attempts": 3,
"node_delete_behavior": "immediate",
"node_drain_to_delete_timeout": 0,
"nodes_table": [
{
"node": "abc1.prod.local:80",
"priority": 1,
"state": "active",
"weight": 1
},
{
"node": "def1.prod.local:80",
"priority": 1,
"state": "disabled",
"weight": 1
},
{
"node": "ghi1.prod.local:80",
"priority": 1,
"state": "disabled",
"weight": 1
},
{
"node": "jkl1.prod.local:80",
"priority": 1,
"state": "active",
"weight": 1
}
],
"note": "",
"passive_monitoring": true,
"persistence_class": "",
"transparent": false
}
}
}


And this powershell script:

$nodesAarray = "abc1.prod.local:80", "jkl1.prod.local:80"
foreach($node in $nodesArray)
{
$nodes_match_and_enabled = $GetNodesResponse.properties.basic.nodes_table | Where { $_.node -eq $node -and $_.state -eq "active" }
if($nodes_match_and_enabled)
{
Write-Output "$node exists in the pool and active"
}
else
{
Write-Output "$node is either not active or the name mismatches"
$global:invalidNodeArray.Add($node)
}
}


In my powershell script I am looping to check the two nodes in my array actually match by value and the state is active. It works as I expect.

However, I am scripting the same exact logic in Python (I am a beginner) but not sure how to approach it. Any idea what the script would look like in Python???

2 Answers
2

Should work in Python 2 or 3, I think:

#!/usr/bin/env python

import sys
import json

res = ""
for line in sys.stdin:
res += line.rstrip()

res_obj = json.loads(res)

nodes = [ 'abc1.prod.local:80', 'jkl1.prod.local:80' ]

invalid_nodes =

for node in nodes:
try:
found = False
test_node_objs = res_obj['properties']['basic']['nodes_table']
for test_node_obj in test_node_objs:
test_node = test_node_obj['node']
if node == test_node:
found = True
break
if found:
sys.stdout.write("%s exists in the pool and activen" % (node))
else:
sys.stdout.write("%s is either not active or the name mismatchesn" % (node))
invalid_nodes.append(node)
except KeyError as ke:
sys.stderr.write("malformed response? check input...n")
pass


Example usage:

$ ./parse_response.py < response.json


Here's an implementation:

jsonObj = {
"properties": {
"basic": {
"bandwidth_class": "",
"failure_pool": "",
"max_connection_attempts": 0,
"max_idle_connections_pernode": 50,
"max_timed_out_connection_attempts": 2,
"monitors": [
"Simple HTTP"
],
"node_close_with_rst": False,
"node_connection_attempts": 3,
"node_delete_behavior": "immediate",
"node_drain_to_delete_timeout": 0,
"nodes_table": [
{
"node": "abc1.prod.local:80",
"priority": 1,
"state": "active",
"weight": 1
},
{
"node": "def1.prod.local:80",
"priority": 1,
"state": "disabled",
"weight": 1
},
{
"node": "ghi1.prod.local:80",
"priority": 1,
"state": "disabled",
"weight": 1
},
{
"node": "jkl1.prod.local:80",
"priority": 1,
"state": "active",
"weight": 1
}
],
"note": "",
"passive_monitoring": True,
"persistence_class": "",
"transparent": False
}
}
}

expectedNodes = {"abc1.prod.local:80", "jkl1.prod.local:80"} # you could use a list here but it's cleaner to use set

for node in expectedNodes:
node_table = jsonObj['properties']['basic']['nodes_table']

node_match = list(filter(lambda t_node: node == t_node['node'], node_table))
is_node_matches_and_active = len(node_match) > 0 and node_match[0]['state'] == "active"
if is_node_matches_and_active:
print('node {} exists and is active'.format(node))
else:
print('node {} not found or not active'.format(node))


Output :

node jkl1.prod.local:80 exists and is active
node abc1.prod.local:80 exists and is active


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