Script question - Python

[DiogoSaraiva]

Hi,

Why this its not working:

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


import os
import time
#....more code.......
with open('log-fonte-alimentacao.txt', 'a') as file:
    file.write("\n\nFonte de Alimentação Desligada\n")
    file.write(os.system('date'))
#...more code......

What should do i do...
Thanks in advance...

Diogo

[ofnuts]

Because the returned value of "os.system('date')" is the return code of the "date" command, not the string the "date" command prints out. If you want the string you should be using os.popen() or the subprocess library.

Byt it would be more efficient to use the functions in the time library.

[Vaphell]

what exactly does not work? does it say anything?
Either way i'd suspect that file.write() expects a string, is os.system() actually returning one?

Also why do you use commandline date command if you can use python native datetime module, superior in this context?
https://docs.python.org/2/library/datetime.html

[DiogoSaraiva]

returns me:
TypeError: expected a character buffer object

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


import os
import time
import datetime


horas = datetime.datetime.now()


with open('date.txt', 'a') as file:
	file.write("\n\nFonte de Alimentação Desligada\n")
	file.write(horas)
file.close()

[ofnuts]

datetime.datetime.now() is a "datetime" object, you have to convert it to a string, for instance using its strftime method:

datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")

[DiogoSaraiva]

Thanks to all. We made it...
Here is the final code: https://github.com/DiogoSaraiva/Priv...alimentacao.py
But the script consumes so much CPU... and the fans always in MAX when I run the script...
any idea??
for less CPU consuming??

Thanks again

[ofnuts]

If you think the script is looping without really executing the sleep() then look at the produced log... Since you write the time in it you can tell if you are actually logging things every 6 seconds or at a much shorter interval. Note that of none of your conditions (GPIO.input(X)) is true, you have a much shorter loop.

Otherwise you may want to ask in a forum dedicated to the Raspberry Pi.

PS: you should avoid all that code duplication...

[DiogoSaraiva]

not logging things every 6 seconds, i guess....
only when i switch ON or OFF my power supply (not of PC, is other power supply like lab power supply) and it send a signal telling that was powered ON or OFF...
only logs when "GPIO.input(7) == True" or "GPIO.input(8) == True" which is when i power ON or OFF my power supply...
And it's not a Raspberry Pi, now I have a mini PC (Giada A51B) that is more powerful than my old raspberry...
in code says virtGPIO, is a virtual GPIO is a arduino connected to the pc (see here more info about virtGPIO).... not a Raspberry pi GPIO...

Thanks

[ofnuts]

At that point it shouldn't be a matter of guessing... If you add a logging instruction after the sleep(1), what do you get in the log?

What actual values are returned by the calls to GPIO (this should be made part of the log)?

[DiogoSaraiva]

in log I get
"Fonte de Alimentação Desligada" and date or "Fonte de Alimentação Ligada" and date ONLY each time I turn off or turn on my power supply

Translations:

Fonte de Alimentação Desligada = Power Supply Off
Fonte de Alimentação Ligada = Power Supply On