adafruit_ads1x15.ads1115 not comaptible with globals()[pkg_trunc] = importlib.import_module(pkg_trunc)

[jrbrearley]

I have sorted out my object syntax issues with adafruit_ads1x15.ads1115. The first attached script ada_dbg1.py.txt which uses simple hardcoded import statements, the creation of ads1115 objects work fine. The second attached script ada_dbg2.py.txt uses a loop to import a variable list of packages, which allows for more graceful error handling & messaging.

globals()[pkg_trunc] = importlib.import_module(pkg_trunc)

The high level observation is that board, busio & adafruit_extended_bus objects continue to be correctly created after the import loop is done. Its just adafruit_ads1x15.ads1115 that does not like this import method.

The same line of code creating ads10 gets error: Traceback (most recent call last): File "ada_dbg2.py", line 33, in ads10 = adafruit_ads1x15.ads1115.ADS1115(i2c_1, address=0x48) AttributeError: module 'adafruit_ads1x15' has no attribute 'ads1115'

When I look at the global variables, from ads_dbg1.py, I see: 'adafruit_ads1x15': <module 'adafruit_ads1x15' from '/home/pi/.local/lib/python3.7/site-packages/adafruit_ads1x15/init.py'>,

When I look at the global variables, from ads_dbg2.py, I see: 'adafruit_ads1x15.ads1115': <module 'adafruit_ads1x15.ads1115' from '/home/pi/.local/lib/python3.7/site-packages/adafruit_ads1x15/ads1115.py'>,

So I tried doing the import without the .ads1115 appended, & got: 'adafruit_ads1x15': <module 'adafruit_ads1x15' from '/home/pi/.local/lib/python3.7/site-packages/adafruit_ads1x15/init.py'>,

But I still get an error. Traceback (most recent call last): File "ada_dbg2.py", line 33, in ads10 = adafruit_ads1x15.ads1115.ADS1115(i2c_1, address=0x48) AttributeError: module 'adafruit_ads1x15' has no attribute 'ads1115'

I went through all 4 permutations of with/without the .ads1115 in the importlib.import_module statement, no luck.

Comments?

ada_dbg1.py.txt ada_dbg2.py.txt print_data.py.txt

[ladyada]

we arent clear that this has anything to do with the library structure or is just a Pythonism.... as the joke goes "if it hurts when you do that, stop doing that" ? use imports the way Python intended em to be used?

[jrbrearley]

Yes, I can work around this in the short/long term.

BTW: I tried the import_module( ... , package=) option, nothing useful happened.

To get a wider viewing of the issue, I posted this article at: https://bugs.python.org/issue42928

[dhalbert]

adafruit_ads1x15.ads1115 is the only module you're importing in this non-standard way that is of the form a.b (dot-separated). I don't know why importlib doesn't like that, but I don't think it has to do with our library. Try a simpler example of some dummy code where you are importing something that has a.b. But this is a Python question, not a library issue, as far as I can tell. Our library is not doing anything unusual.

[jrbrearley]

I tried loading adafruit_ads1x15.analog_in via importlib.import_module and it works fine, see attached power_monitor_rpi.py.txt below.

When you run the script, the globals data shows:

'adafruit_extended_bus': <module 'adafruit_extended_bus' from '/home/pi/.local/lib/python3.7/site-packages/adafruit_extended_bus.py'>, 

'adafruit_ads1x15.analog_in': <module 'adafruit_ads1x15.analog_in' from '/home/pi/.local/lib/python3.7/site-packages/adafruit_ads1x15/analog_in.py'>, 

'adafruit_ads1x15': <module 'adafruit_ads1x15' from '/home/pi/.local/lib/python3.7/site-packages/adafruit_ads1x15/__init__.py'>}

The first two packages point to the lowest level .py file with code in them, but the adafruit_ads1x15 points to an (empty) --init--.py file. Maybe this is a clue?

power_monitor_rpi.py.txt