Raspberry Pi Forums

Posted: **Thu Feb 07, 2019 12:33 pm**

Hi All

I would like to run the shell command;

vcgencmd measure_temp

... which runs perfectly in the terminal, within a Python script, assigning that to a variable for subsequent

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cpu_temp = subprocess.check_output("vcgencmd measure_temp", shell=True)

I tried the above (obtained from elsewhere) but the result returned is not what I expected, which is;.

b"temp=52.6'C/n"

Could someone offer some advice please, many thanks.

Posted: **Thu Feb 07, 2019 1:48 pm**

If you just want the temperature value you can do it like this

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with open("/sys/class/thermal/thermal_zone0/temp", "r") as file:
    temp = float(file.read())
tempC = temp/1000
print (tempC)

but if you want the output as a string including the text then this code

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with open("/sys/class/thermal/thermal_zone0/temp", "r") as file:
    temp = float(file.read())
tempC = temp/1000

tempC = str(tempC)
output = "temp=" + tempC + "'C"
print (output)

Posted: **Thu Feb 07, 2019 4:10 pm**

If you wish to us Popen, this will work:

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import subprocess

# execute the command using Popen
sb = subprocess.Popen(['vcgencmd', 'measure_temp'], stdout=subprocess.PIPE)

# get the command output
cmd_out = sb.communicate()

# convert from byte string to string
temp = cmd_out[0].decode()
print(temp)

And here is the output when I run this:

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pi@RPi3BP:~ $ python3 pop.py
temp=44.0'C

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