SyntaxError: invalid syntax ??

[korenron]

Hello ,
starnge problem
I have a working python code that print me canbus data
today I enter the code to a new machine and I get this error (just copied the code)

def ReadCanBusData():
    bus = can.interface.Bus(channel='can0', bustype='socketcan')
    while True:
        try:
            message = bus.recv(10)
        except Exception as e:
            print('error in CanBus!')
        else:
            if message is None:
                print('TimeOut!')
            else:
                TS = datetime.datetime.now()
                pid_temp = message.arbitration_id
                pid_int = int(pid_temp)
                data_byte = message.data
                try:
                    data_temp = [f"{byte:02x}" for byte in data_byte]
                except Exception as e:
                    print(e)
                Data = ' '.join(data_temp)
                PID = f"{pid_int:08X}"
                PID = PID.upper()
                print(str(TS) + ": " + PID + ": " + Data)

when I try to run it I get :

 python3 ReadCanbus.py
  File "ReadCanbus.py", line 39
    data_temp = [f"{byte:02x}" for byte in data_byte]
                             ^
SyntaxError: invalid syntax

and also this (when I disable line 39,40):

 python3 ReadCanbus.py
  File "ReadCanbus.py", line 41
    PID = f"{pid_int:08X}"
                         ^
SyntaxError: invalid syntax

again - it's the same file running on other machine

waht is this , and what is wrong?
Thanks ,

[Gribouillis]

f-strings appeared in Python 3.6. The other machine may be running an older version of Python.

[snippsat]

Run this code.

import sys

print(sys.version)

data_byte = b'123'
data_temp = [f"{byte:02x}" for byte in data_byte]
print(data_temp)

Output:
3.10.0 (tags/v3.10.0:b494f59, Oct  4 2021, 19:00:18) [MSC v.1929 64 bit (AMD64)]
['31', '32', '33']

So as mention need a version newer that Python 3.6(f-string was new there),now you see which version before get SyntaxError.

[korenron]

ok
I thought it from 2.6 and UP

this is what I have :

3.5.3 (default, Apr  5 2021, 09:00:41)

so just use apt-get update on the PI an it will update the python ?
or I need to do something else?

Thanks,

[snippsat]

How To Install the Latest Python Version on Raspberry Pi?

I use pyenv for all OS that is not Windows,my tutorial.
How to Setup Raspberry Pi OS: Bullseye like a Python Pro

[korenron]

Thank you

[Gribouillis]

Your OS may also have packages for python3.8 or python3.9 which you could also install.

[korenron]

I did everything it saidin the guide

https://raspberrytips.com/install-latest-python-raspberry-pi/

but when it still show me the oldest version

pi@localhost:~ $ python3 --version
Python 3.5.3

[snippsat]

https://raspberrytips.com/install-latest...pberry-pi/

Always run a Python script with the exact version you want to use, for example:

python3.9 myscript.py

Read further how to change the link.

Link the version your want to use instead:

sudo ln -s /usr/local/bin/python3.9 python

[korenron]

this is what I got :

 sudo ln -s /usr/local/bin/python3.9 python3
sudo: unable to resolve host localhost: No such file or directory

this is an old PI3 , maybe I can't make it work ?

maybe I can do something else in the code so it will work with version 3.5?
just this part ?

  PID = f"{pid_int:08X}"

I have found I can do this :

PID = str('{:08x}'.format(pid_temp))

and it's working

but how can I do it for this part:

data_temp = [f"{byte:02x}" for byte in data_byte]

I have try :

for byte in data_byte:                 
                    test = str('{byte:02x}'.format(byte))
                    print(test)
 

but I'm wrong....


Thanks,