microemu: Seamlessly run MicroPython code using Python 3

[vshymanskyy]

While developing MicroPython modules, I found it really convenient to be able to run the same code in Python 3 (for debugging and testing purposes). However, MicroPython environment and builtin modules differ (slightly) from that of the "big" Python.

Previously, I was adding some bits of shim code directly into my scripts. Recently I came up with microemu and decided to publish it.

Here’s how microemu can be used to run the default example from aiodns, which performs DNS resolution asynchronously:

$ microemu examples/simple/main.py 
=== Resolving google.com ===
  IPv4:
    (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('216.58.215.78', 80))
    (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('216.58.215.110', 80))
    (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('142.251.39.46', 80))
  IPv6:
    (<AddressFamily.AF_INET6: 10>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('2a00:1450:401b:806::200e', 80, 0, 0))
    (<AddressFamily.AF_INET6: 10>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('2a00:1450:401b:807::200e', 80, 0, 0))
    (<AddressFamily.AF_INET6: 10>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('2a00:1450:400d:80d::200e', 80, 0, 0))
...

💡 Comments and ideas are welcome!
P.S: am I reinventing the wheel?

[jonnor]

Interesting! In which cases would you prefer to use this over running "micropython examples/simple/main.py" (using the Unix port)?

[vshymanskyy]

It allows catching implementation-specific details of Python. For example, the representation of addrinfo is completely different in Python3 and MicroPython. It also allows for direct debugging.

[zcattacz]

I run a MCU targeting upy mqtt client on both MCU and Linux boxes as user service.
I'd to see a one-liner option e.g. from patcher import monkey_patch_cpython or from patcher import monkey_patch_unixport. After that, no more conditional import mess.
Ideally the unixport shims would be unnecessary in the future but it was still needed for e.g. unique_id, wifi, bt etc.

[vshymanskyy]

@zcattacz I believe microemu is a one-liner solution:

microemu your-script.py

[Josverl]

Wrt to step- debugging i have used the .py versions of the MicroPython stubs to allow importing the MCU only modules which are not available in CPython nor in MicroPython-Unix.

The stubs are not full shims by definition, but I've found it simple to add a return value in where needed.