If a python program takes / as the parameter of a function, micropython reports a SyntaxError. See the following case. This test case can work normally on CPython.

MicroPython_exampe.py

def run_in_thread(func, /, *args, **kwargs):
    pass

The expected behavior:

CPython 3.9.0: work normally

The actual output:

Traceback (most recent call last):
  File "/home/xxm/Desktop/MicroPython_exampe.py", line 55
SyntaxError: invalid syntax

Test Environment:

Unix port,
MicroPython v1.20.0-162-gd080d427e on 2023-06-08; linux [GCC 7.5.0] version
Ubuntu 18.04
CPython 3.9.0