Why no result from os.popen() when script is run from crontab?

Question

When I run this Python3 script from the command line or from Thonny I get correct results. When I run it through crontab the variables ipaddress an ssid stay empty.

Can anyone tell me why? Any suggestions to solve it?

import dweepy, os

ipaddress = os.popen("ifconfig wlan0 | grep 'inet' | awk '/inet / {print $2}'").read()
ssid = os.popen("iwconfig wlan0 | grep 'ESSID' | awk '{print $4}' | awk -F\\\" '{print $2}'").read()

data = ssid[:-1] + ' ' + ipaddress[:-1]

dweepy.dweet_for('NorthWestern', {'here I am':data})

This script should let me know the ip address and the SSID of the wifi to which my headless Pi is connected.

Edit: this is the line in crontab:

* * * * * python3 /home/pi/PythonON5MF/send_ip_v001.py &

Answer 1

I found the solution... add sudo inside de os.popen() command:

ipaddress = os.popen("sudo ifconfig wlan0 | grep 'inet' | awk '/inet / {print $2}'").read()