TypeError: can't create 'module' instances

[klaasbrant]

I did write some micropython classes to set the RTC with a NTP server and a class to handle the timezone time including handling of daylight saving time. Then I thought why not base the last one on the buildin time module class so localtime finally get a correct value. But that doesn't work:

import utime
class EZTime(utime):
def init(self,tz=""):
self.timezone(tz)
super.init()

Traceback (most recent call last):
File "", line 3, in
TypeError: can't create 'module' instances

Is this a micropython restriction? Micropython classes cannot extend a class in a C language module?

[stinos]

Micropython classes cannot extend a class in a C language module?

That is possible, but you're trying to inherit a module, not a class. There's no such thing as a 'module class' (as far as I'm aware). I'm not sure even CPython can do that. You can create a new module which hass all members of another module (e.g. https://softwareengineering.stackexchange.com/questions/298019/how-to-achieve-inheritance-when-using-just-modules-and-vanilla-functions-in-pyth). Or you can inherit a class. Btw isn't timezone in the datetime module?

[klaasbrant]

There is a datetime in RTC (ESP32) but no timezone in there. Just a simple class to obtain a datetime tuple.

The stack overflow topic discusses function inside a module. But utime is a class not a function.
You can do dir(utime) and it shows the fact that it is a class and all it's methods.
The stack overflow is right a from import * gives access to all the functions, classes and variables in
And if you do that and then create your own function with the same name it will overwrite the imported one.
That is why import * is quick and dirty and might backfire one day.

doing:

from utime import *
class EZTime(utime):
def init(self,tz=""):
self.timezone(tz)
super.init()

gives the same error. So it is not an import problem... As if you cannot extend a class from the c-language module in micropython?

[jimmo]

@stinos is right, you cannot do this in CPython either:

>>> import time
>>> class X(time):
...   pass
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: module() takes at most 2 arguments (3 given)

[stinos]

You can do dir(utime) and it shows the fact that it is a class and all it's methods.

dir just shows members, that alone doesn't prove it's a class. I don't know what platform you're on, but don't you get

>>> import utime
>>> utime
<module 'utime'>

?

As opposed to for example

>>> list
<class 'list'>

[klaasbrant]

OMG so utime is just a module with a bunch of functions?! Confusing, some are classes like RTC, I2C, PWM and some are not like utime. I will create methods with similar names for my function because I hate that you depend on the import order.

I thought utime was a class because dir showed class I wonder where that comes from? Next time I will do a type() before I ask questions ;-)

[stinos]

thought utime was a class because dir showed class I wonder where that comes from?

Ah, __class__, yes I can see how that could cause confusion. That's essentially the same functionality as type(<something>).