MicroPython imports a binary format class library through the import directive?

[Mars-CN]

MicroPython imports a binary format class library through the import directive? Just like Python, the class library file (mylib.so) that uses C/C++ extension can be used directly after importing it through import mylib, but MicroPython can only import files in .py or .mpy format. I don’t know if it can Import files in so format?
Or, where should I start modifying the source code?
PS: This class library is loaded dynamically, and I don’t want to compile it into MicroPython’s firmware.

MicroPython 通过 import指令导入一个二进制格式的类库？就像Python 一样，使用C/C++ 扩展的类库文件(mylib.so) 通过 import mylib 导入后就可以直接使用了，但是 MicroPython只能导入 .py或者.mpy 格式的文件，不知道是否能导入 so 格式的文件？
或者，我应该从哪里入手修改源代码？
PS：这个类库是动态化加载进去的，我不想将它编译到 MicroPython的固件中。

[peterhinch]

CPython does this via ctypes. The equivalent library in MicroPython is uctypes. Unfortunately this does not have cdll or CDLL objects so it seems that using .so files is not possible.

[jonnor]

If you have access to the C/C++ code, you can build a dynamic native module. This can be built separately from main firmware, copied to device and loaded at runtime. See the documentation https://docs.micropython.org/en/latest/develop/natmod.html#supported-features-and-limitations and the examples https://github.com/micropython/micropython/tree/master/examples/natmod

[Mars-CN]

Thank you very, very, very much!!!

[Mars-CN]

@jonnor
I encountered some issues because I needed to use the content of string. h in the code, but there was a prompt during compilation
LinkError: build/mpfile.o: undefined symbol: memset A type of error
I also encountered the same error when using some libraries in MicroPython
LinkError: build/mpfile.o: undefined symbol: mp_vfs_listdir

How should these be resolved?
Do I feel that it is related to static class libraries