Pi 3 and PYTHONPATH
4553 Views - Created 13/05/2016
13/05/2016
Posted by:
squiregeek
Location:
North Carolina, USA
I've installed the ADC board and can run the readvoltage example script under python3. But when I try to run a script of my own, it chokes on from ABE_ADCPi import ADCPi, complaining no such file or directory. Using the file name in the home/pi folder I've added the following lines to /.bashrc:PATH="${PATH}:home/pi/ABElectronics_python3_libraries/ADCPi"export PATHPYTHONPATH="${PYTHONPATH}:home/pi/ABElectronics_python3_libraries/ADCPi"export PYTHONPATHls $PATH and ls $PYTHONPATH both retrun the error: no such file or directory.What am I missing?Thanks for your help.
13/05/2016
Posted by:
andrew
Location:
United Kingdom
Try changing the path to be /home/pi/ABElectronics_Python3_Libraries/ADCPi
Linux is case sensitive so ABElectronics_python3_libraries with a lowercase P and L would be seen as a different directory.
Linux is case sensitive so ABElectronics_python3_libraries with a lowercase P and L would be seen as a different directory.
13/05/2016
Posted by:
squiregeek
Location:
North Carolina, USA
Thanks, Andrew. The directory added at install is ABElectronics_python3_libraries. Is PATH able to locate ABElectronics_Python3_Libraries?
13/05/2016
Posted by:
squiregeek
Location:
North Carolina, USA
Andrew,I went back through the process and founD the git clone you referred to. I put the ABElectronics_Python3_Libraries in $PYTHONPATH in .bashrc and still no joy. I'll try a few variations and see if something will work. Progress... Jim
13/05/2016
Posted by:
andrew
Location:
United Kingdom
Python 3 should work with PATH. I just tried setting up a path to the python 3 ADCPi library following our Python Path tutorial and after rebooting and copying the read voltage demo to the root directory I could run the demo and read from the ADC Pi.
13/05/2016
Posted by:
squiregeek
Location:
North Carolina, USA
Andrew, this may be a clue to what I'm doing wrong. I changed the .bashrc entry to PATH="${PATH}:/home/pi/" and ls PATH still showed no file or directory. I'm clearling missing something here. No matter what directory I put in PATH or PYTHONPATH, it shows up when I run ls, but it's not recognized. I'm sure it's something simple, but I just can't see it.
13/05/2016
Posted by:
squiregeek
Location:
North Carolina, USA
Here's what I get after entering ls:ls: cannot access :/home/pi/: no such file or directory.My entry in bashrc is PATH="${PATH}:/home/pi/"PATH cannot find my home directory. Clearly I've entered something wrong.
14/05/2016
Posted by:
andrew
Location:
United Kingdom
Can you try running echo $PATH and see if that returns anything? On my raspberry pi it is returning
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/games:/usr/games:/home/pi/Desktop/ABElectronics_Python3_Libraries/ADCPi
while ls PATH does return
ls: cannot access PATH: No such file or directory
If you try ls /home/pi/ABElectronics_python3_libraries/ADCPi does that go to the correct directory?
Also, are you editing the .bashrc file in your home directory or in the root? In the first post you mentioned /.bashrc . It should be the file in your home directory ~/.bashrc that you need to edit which you can get to with
sudo nano ~/.bashrc
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/games:/usr/games:/home/pi/Desktop/ABElectronics_Python3_Libraries/ADCPi
while ls PATH does return
ls: cannot access PATH: No such file or directory
If you try ls /home/pi/ABElectronics_python3_libraries/ADCPi does that go to the correct directory?
Also, are you editing the .bashrc file in your home directory or in the root? In the first post you mentioned /.bashrc . It should be the file in your home directory ~/.bashrc that you need to edit which you can get to with
sudo nano ~/.bashrc
14/05/2016
Posted by:
squiregeek
Location:
North Carolina, USA
Andrew,I ran 'echo $PATH' and it returned the complete path without errors. 'echo $PYTHONPATH' also worked. I still was unable to run /home/pi/demo-readvoltage.py from the terminal but could from IDLE. I've been using 'sudo python3 demo-readvoltage.py' because an earlier version of the script used GPIO under Wheezy (no longer needed under Jessie). When I dropped the 'sudo' both the demo program from examples and my test script worked.I suspect that improper use of 'sudo' was the root of my problem. Perhaps it was referencing root's bashrc. Using 'ls $PATH' (as suggested on a couple of forums) instead of 'echo $PATH' led me astray. I am deeply grateful for your help. My project is back on track thanks your patient help.
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