Raspberry Pi SoC monitoring script

pi_soc_monitor.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

import os
import csv
import time

delay = 2
csv_file = "pi_soc_results.csv"

elapsed = 0

def write_csv(mode, value):
    with open (csv_file, mode) as csv_file_opened:
        writer = csv.writer(csv_file_opened)
        writer.writerow(value)
       
    csv_file_opened.close()

def extract_float_value(text, start, end):
    result = ""
    
    if end == "":
        result = text[text.find(start)+1:len(text)]
    else:
        result = text[text.find(start)+1:text.find(end)]
    
    return float(result)

def get_temp():
    
    temp_r = os.popen("vcgencmd measure_temp").readline()
    temp_f = extract_float_value(temp_r, "=", "'")
    
    return temp_f

def get_clock(part):
    
    clock_core_r = os.popen("vcgencmd measure_clock " + part).readline()
    clock_core_f = extract_float_value(clock_core_r, "=", "")/1000000
    
    return clock_core_f

def get_volt():
    
    volt_r = os.popen("vcgencmd measure_volts core").readline()
    volt_f = extract_float_value(volt_r, "=", "V")
    
    return volt_f

print
print(" Raspberry Pi SoC values :")
print(" =========================")
print

write_csv("w", ["temp", "core freq", "arm freq", "volt", "sec"])

while True:
 
    values = [get_temp(), get_clock("core"), get_clock("arm"), get_volt(), elapsed]
    
    print(" {0:.0f}°C - {1:.0f}/{2:.0f} MHz - {3:.2f} V".format(values[0], values[1], values[2], values[3]))
    write_csv("a", values)
        
    time.sleep(delay)
    elapsed += delay