Accessing system_profiler plist items using plistlib

Question

I'm trying to access the serial_number key of the first _items array in the generated plist:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<array>
    <dict>
        <key>_SPCommandLineArguments</key>
        <array>
            <string>/usr/sbin/system_profiler</string>
            <string>-nospawn</string>
            <string>-xml</string>
            <string>SPHardwareDataType</string>
            <string>-detailLevel</string>
            <string>full</string>
        </array>
        <key>_SPCompletionInterval</key>
        <real>0.15617406368255615</real>
        <key>_SPResponseTime</key>
        <real>0.18982398509979248</real>
        <key>_dataType</key>
        <string>SPHardwareDataType</string>
        <key>_detailLevel</key>
        <string>-2</string>
        <key>_items</key>
        <array>
            <dict>
                <key>serial_number</key>
                <string>C0**</string>
            </dict>
        </array>
    </dict>
</array>
</plist>

Here is the Python code:

    def get_serial_number():
        import plistlib
        cmd = ['system_profiler', 'SPHardwareDataType', '-xml']
        plist = subprocess.check_output(cmd)
        with open('hardware.plist', 'wb') as fp:
            plistlib.dump(plist, fp)
        with open('hardware.plist', 'rb') as fp:
            pl = plistlib.load(fp, fmt=None, dict_type=dict)
            serial = pl[0]['_items'][0]['serial_number']
        return serial

The error I receive is: 'int' object is not subscriptable. I'm assuming this is because of the way I'm trying to access the keys of the plist on line 9, but I cannot figure it out.

Any assistance would be greatly appreciated!

Answer 1

That was lots of fun to work out! I think you want this to get the serial number from a system_profiler plist

import plistlib
import subprocess

cmd = ['system_profiler', 'SPHardwareDataType', '-xml']
plist = subprocess.check_output(cmd)

pl = plistlib.loads(plist, fmt=None, dict_type=dict)
print(pl[0]['_items'][0]['serial_number'])

---

You can also do it without plistlib like this:

import subprocess

cmd = ['system_profiler', 'SPHardwareDataType']
profile = subprocess.check_output(cmd).decode('utf-8')
for line in profile.splitlines():
   if 'Serial Number' in line:
       serial = line.split()[-1]