[split] Check presence of a file

[pascale]

Hi,
I have been trying to create something like this for a while to use with a flask app, I am trying to learn python3 so I am lost with the above, I want to create a module that I can import

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def read_sensor(sensorID)   tempfile = open("/sys/bus/w1/devices/"+ sensorID +"/w1_slave")    thetext = tempfile.read()    tempfile.close()    tempdata = thetext.split("\n") [1].split(" ")[9]    temperature = float(tempdata[2:])    temp = temperature / 1000    print (temp"sensorname")

with a seperate file with a list of the sensors

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# Execute DS18B20 function for sensor ID's below.     solar_panel = float(read_ds18b20('28-0516a3ff90ff'))       top_cyl = float(read_ds18b20('28-0317003f1cff'))       flow_panel = float(read_ds18b20('28-0416c4a3a0ff'))

(I have stolen the code from above) I want the name of the sensor to print out with its temperature. I know the code needs to be modified.
Can any one tell me if the first code will work as a module to be imported ie:
import readsensor as sensorID ??? and if then I would be able to call the function with:

read_sensor(solar_panel) ???
so that I can then use the returned value to compare with another to operate the solar pump ie:

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while solar_panel + 5 > flow_panel GPIO.output(relay,GPIO.HIGH)

As you can see I have a lot to learn!!!
I am using a pi zero 4gb card stretch 9 lite via ssh
Any help greatly wanted
Paul

[gontajones]

If your first code is in a file, for example, called mySensorModule.py.
You can import all of its content with:

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import mySensorModule as mS # To call read_sensor() sensorID = 1 mS.read_sensor(sensorID)

Or...

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from mySensorModule import read_sensor # Call read_sensor() sensorID = 1 read_sensor(sensorID)

[pascale]

Hi gontajones
Thank you for your reply, I will be using two files as modules that will be imported into a flask app and other other apps, the first module is called mySensorModule.py

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def read_sensor(sensorID)   tempfile = open("/sys/bus/w1/devices/"+ sensorID +"/w1_slave")    thetext = tempfile.read()    tempfile.close()    tempdata = thetext.split("\n") [1].split(" ")[9]    temperature = float(tempdata[2:])    temp_sensor = temperature / 1000    print (temp_sensor)

the second file called mySensors.py will have a list of sensors

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# Execute DS18B20 function for sensor ID's below. sensorsID {     solar_panel = float(read_ds18b20('28-0516a3ff90ff')),       top_cyl = float(read_ds18b20('28-0317003f1cff')),     flow_panel = float(read_ds18b20('28-0416c4a3a0ff')), }

So if i use your script like this

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from mySensorModule import read_sensor from mySensors import sensorsID # Call read_sensor() sensorID = solar_panel read_sensor(sensorID)

Will this work ??????? what needs to be corrected in this script ????
I am trying to learn python so that I can Make a home heating app using a raspberry pi, and then after that many other things !!! my daughter introduced me to pi, (to my wifes discuss as I am now addicted to learning Python)
Tommorrow is Sunday My wife is out all morning so I really want to make good progress if I can, All help greatly needed,
regards Paul
(sorry I hijacked another persons thread, but I thought that as it was about ds18b20 sensors it made sense rather than start a new one!

[gontajones]

The first file:

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def read_sensor(sensorID)    tempfile = open("/sys/bus/w1/devices/"+ sensorID +"/w1_slave")    thetext = tempfile.read()    tempfile.close()    tempdata = thetext.split("\n")[1].split(" ")[9]    temperature = float(tempdata[2:])    temp_sensor = temperature / 1000    print (temp_sensor)

Seconde file:

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# Execute DS18B20 function for sensor ID's below. # As sensorsID is a dictionary, you declare it like this: sensorsID = {     'solar_panel': float(read_ds18b20('28-0516a3ff90ff')),       'top_cyl': float(read_ds18b20('28-0317003f1cff')),     'flow_panel': float(read_ds18b20('28-0416c4a3a0ff')) }

Now, in the last file:

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from mySensorModule import read_sensor from mySensors import sensorsID # Accessing a dictionary: dict_name[key] = value sID = sensorsID['solar_panel'] read_sensor(sID) # Or... read_sensor(sensorsID['solar_panel'])

PS: Raspi is so cool!

[pascale]

gontajones,
Thank you so much, I can now use this to display the temperatures with a flask app, to local network, and then I can create another file to operate a relay for the solar panel pump. I want to keep things a simple as possible, rather than having one large file with lots of script, i will have several files so that I can easily adapt this to other uses and update sensor names quickly, if needed. I am so excited, tomorrow I can really get on !!!
Thank you again for your help
Regards Paul
I am now reading about flask apps ready for tommorrow, and yes if only raspi was about 40 years ago !!

[gontajones]

Just be careful with naming...

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from mySensorModule import read_sensor from mySensors import sensorsID   print(sensorsID) # Will print the dict from mySensors   # But if you do something like: sensorsID = 0 # Your import will be override... print(sensorsID) # Will print 0

[pascale]

hi Gontajones,
I think I have understood what you are saying, Thank you again,
Kind regards
Paul

[pascale]

OK, Its sunday morning,
There was an error in my origional code for the sensor list as I stole this from another thread, check presence of file

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# Execute DS18B20 function for sensor ID's below. sensorsID {     solar_panel = float(read_ds18b20('28-0516a3ff90ff')),       top_cyl = float(read_ds18b20('28-0317003f1cff')),     flow_panel = float(read_ds18b20('28-0416c4a3a0ff')), }

When I tried this out in my test program I got lots of errors (heat.py)

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from mySensorModule import read_sensor from mySensors import sensorsID # accessing a dictionary: dict_name[key] = value sID1 = sensorsID['solar_panel'] sID2 = sensorsID['cyl_bottom']   while 1:     sID1 + 5 > sID2     print("it's hot") else:     print("got it wrong again dad")

so after many changes this new code worked

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# Execute DS18B20 function for sensor ID's below. # As sensorsID is a dictionary, you declare it like this: sensorsID = {     'solar_panel': '28-0516a3ff90ff',     'top_cyl': '28-0317003f1cff',     'flow_panel': '28-0416c4a3a0ff',     'cyl_bottom': '28-03170017b5ff' }

gonatajones I followed your script and this is the modified version, But heat.py only works if I remove the "+ 5" from the "while 1:" loop. If I leave that in I get;

Traceback (most recent call last):
File "temp.py", line 8, in <module>
sID1 + 5 > sID2
TypeError: Can't convert 'int' object to str implicitly

I want to import RPi.GPIO to operate a relay to work the solar pump automatically.
Some may say "Whytry to reinvent the wheel" search google an you will fin many tutorials tha give you the code, and I have done this, But you learn little just copying others you have got to try it youself to learn!
So keep watching, and I will post all changes to my Script as I go.
But any and all help is greatly needed!
Kind regards
Paul

---

Ok,
I tried :

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if (true) isnstance(sID1, int)     print("true")

And I got "true" so I did the same for "x = 5" and got true so I changed my code to

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from mySensorModule import read_sensor from mySensors import sensorsID # accessing a dictionary: dict_name[key] = value sID1 = sensorsID['solar_panel'] sID2 = sensorsID['cyl_bottom'] x = 5   while 1:     sID1 + x > sID2     print("it's hot") else:     print("got it wrong again dad")

And I still get the same error message as above I will keep working!!
Regards Paul
ps I am now a "programmer named tim", I think I've a long way to go yet!!!

---

Big problem!
My code

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from mySensorModule import read_sensor from mySensors import sensorsID # accessing a dictionary: dict_name[key] = value sID1 = sensorsID['solar_panel'] sID2 = sensorsID['cyl_bottom'] x = 5    while 1:     sID1 + x > sID2     print("it's hot") else:     print("got it wrong again dad")

was comparing the id's of each sensor not the temperatures!
Back to the drawing board!
Regards
Paul

[pascale]

gontajones
I should have read all your answers not just the last
new script new error code

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from mySensorModule import read_sensor from mySensors import sensorsID import time   # accessing a dictionary: dict_name[key] = value sID1 = sensorsID['solar_panel'] sID2 = sensorsID['cyl_bottom']   while 1:     read_sensor(sID1) > read_sensor(sID2)     print("it's Hot!")     time.sleep(1) else:     print("Got it wrong again Dad")

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35.875
Traceback (most recent call last):
File "temp.py", line 10, in <module>
read_sensor(sID1) > read_sensor(sID2)
TypeError: unorderable types: NoneType() > NoneType()

I have got the temperatures but they are not being compared
Regards Paul
I love learning

[snippsat]

The code you have posted of function read_sensor(sensorID) missing : SyntaxError.
The read read_sensor(sensorID) should also return a value as you need that later when comparing.

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def read_sensor(sensorID):     tempfile = open("/sys/bus/w1/devices/"+ sensorID +"/w1_slave")     thetext = tempfile.read()     tempfile.close()     tempdata = thetext.split("\n")[1].split(" ")[9]     temperature = float(tempdata[2:])     temp_sensor = temperature / 1000     return temp_sensor  # Not print()

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35.875
Traceback (most recent call last):
File "temp.py", line 10, in <module>
read_sensor(sID1) > read_sensor(sID2)
TypeError: unorderable types: NoneType() > NoneType()

When read_sensor function has no return value only print(),it will return None.