Don't understand fundamental concept of Pymakr and modules

[Patrick Keogh]

I wasn't sure whether to put this in Pymakr or just "Getting Started"...

I know Python well, but despite reading lots of introductory documentation there is something fundamental that I don't understand. I have Atom and Pymakr running fine. I can load a Python module as main.py and it executes just fine. I can type Python statements to the ">>>" and they work fine too.

My program will use MQTT, and so I found the module and I have it as umqtt.py. I copied it to .atom/packages/umqtt/umqtt.py
I have a project that has three files:

boot.py (empty)
main.py (38 lines of code)
lib/umtqq.py (205 lines of code)

The first few lines of main.py are

print("Init of main")
import pycom
pycom.heartbeat(False)
pycom.rgbled(0xFF0000)  # Green
from umqtt import MQTTClient
from network import WLAN
import machine
import time

So I use Pymakr to

• Format flash storage

• With the project selected, Upload Project to Device

>>> 
Reading file status
Failed to read project status, uploading all files
Creating dir Garage
Creating dir Garage/lib
[1/3] Writing file Garage/boot.py (0kb)
[2/3] Writing file Garage/lib/umqtt.py (6kb)
[3/3] Writing file Garage/main.py (0kb)
Upload done, resetting board...
OKets Jun  8 2016 00:22:57

rst:0x7 (TG0WDT_SYS_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff8020,len:8
load:0x3fff8028,len:2140
ho 0 tail 12 room 4
load:0x4009fa00,len:19760'''

That all looks OK to me, but then if I select main.py and click Run I get

>>> 
>>> 
Init of main
Traceback (most recent call last):
  File "<stdin>", line 7, in <module>
ImportError: no module named 'umqtt'
>
Pycom MicroPython 1.20.2.r1 [v1.11-a5aa0b8] on 2020-09-09; WiPy with ESP32
Pybytes Version: 1.6.0
Type "help()" for more information.
>>> 
>>> 

So main.py runs and the LED is indeed red, but the import fails. So what am I not understanding about importing modules?

[p s]

This is a classic.
You have to change your import from

from umqtt import MQTTClient

to

from lib.umqtt import MQTTClient

Thit will solve the problem.

However, I would recommend creating an empty file called __init__.py inside your lib folder. This way you just need to make a reference to the package where your libraries are, like

from directory.filename import Myclass

This might be helpful if you need to import something from a directory one level up.

[Manuel Ricardo Alfonso Sanchez]

@Patrick-Keogh said in Don't understand fundamental concept of Pymakr and modules:

Garage

Hi. I suggest you to upload files directly in flash. As I seen in your upload sketch it appears a Garage folder and inside the lib folder and so on.