system_info.py

import subprocess
import os


def get_ram():
    "Returns a tuple (total ram, available ram) in megabytes. See www.linuxatemyram.com"
    try:
        s = subprocess.check_output(["free", "-m"])
        lines = s.split("\n")
        return (int(lines[1].split()[1]), int(lines[2].split()[3]))
    except:
        return 0


def get_process_count():
    "Returns the number of processes"
    try:
        s = subprocess.check_output(["ps", "-e"])
        return len(s.split("\n"))
    except:
        return 0


def get_up_stats():
    "Returns a tuple (uptime, 5 min load average)"
    try:
        s = subprocess.check_output(["uptime"])
        load_split = s.split("load average: ")
        load_five = float(load_split[1].split(",")[1])
        up = load_split[0]
        up_pos = up.rfind(",", 0, len(up) - 4)
        up = up[:up_pos].split("up ")[1]
        return (up, load_five)
    except:
        return ("", 0)


def get_connections():
    "Returns the number of network connections"
    try:
        s = subprocess.check_output(["netstat", "-tun"])
        return len([x for x in s.split() if x == "ESTABLISHED"])
    except:
        return 0


def get_temperature():
    "Returns the temperature in degrees C"
    try:
        s = subprocess.check_output(["/opt/vc/bin/vcgencmd", "measure_temp"])
        return float(s.split("=")[1][:-3])
    except:
        return 0


def get_ipaddress():
    "Returns the current IP address"
    arg = "ip route list"
    p = subprocess.Popen(arg, shell=True, stdout=subprocess.PIPE)
    data = p.communicate()
    split_data = data[0].split()
    ipaddr = split_data[split_data.index("src") + 1]
    return ipaddr


def get_cpu_speed():
    "Returns the current CPU speed"
    f = os.popen("/opt/vc/bin/vcgencmd get_config arm_freq")
    cpu = f.read()
    return cpu


print "Free RAM: " + str(get_ram()[1]) + " (" + str(get_ram()[0]) + ")"
print "Nr. of processes: " + str(get_process_count())
print "Up time: " + get_up_stats()[0]
print "Nr. of connections: " + str(get_connections())
print "Temperature in C: " + str(get_temperature())
print "IP-address: " + get_ipaddress()
print "CPU speed: " + str(get_cpu_speed())

The original script can be found here:
http://cagewebdev.com/raspberry-pi-showing-some-system-info-with-a-python-script/