Let's break down what's causing this error and how to fix it step by step.

The Root Cause #

You're getting this error because you're passing a pre-serialized JSON string to the json parameter of requests.post(). The json parameter expects a Python dictionary, not a string. When you pass the string, your API receives it as a JSON string value (not an object), so request.json becomes a string instead of a dictionary. Strings don't have a .get() method, hence the error.

Step-by-Step Fixes #

1. Update powershell.py #

Remove the json.dumps() call and keep the dataPw dictionary as a native Python object (we'll let requests handle the JSON serialization):

import subprocess
import sys
import json
from flask import Flask, json

processDefender = subprocess.Popen(["powershell", "get-process | Select-string lsass"], stdout=subprocess.PIPE, shell=False)
resultDef = processDefender.communicate()[0].decode('utf-8').strip()
dataPw = {}
dataPw['Defender'] = resultDef

# Optional: Print JSON for debugging, but don't assign to a string variable
print(json.dumps(dataPw, sort_keys=True, indent=4))

2. Fix run.py #

Use the dataPw dictionary directly in the requests.post() call instead of the string dataFn:

import os
import json
import requests
import subprocess
from powershell import *
from DetectOS import *

# Pass the Python dict to the json parameter
r = requests.post('http://127.0.0.1:5000/connection', json=dataPw, headers={'Content-type': 'application/json', 'Accept': 'text/plain'})

Why This Works #

When you pass a Python dictionary to the json parameter, requests automatically serializes it to valid JSON and sets the correct headers. Your API endpoint will then receive a JSON object, so request.json will be a Python dictionary—allowing you to use .get() or any other dictionary methods without errors.

Side Note (Optional Process Query Improvement) #

Your PowerShell command uses Select-string lsass to search for the string "lsass" in process output. If you want to directly retrieve the lsass process details, use this command instead:

get-process lsass

This will return the actual process object rather than searching for the string in output lines.

内容的提问来源于stack exchange，提问作者Ricardo Pinto