I just wanted to create this issue as a placeholder for certain c-extension functions used by pyodbc that are going to be removed in upcoming Python versions. Here is the list I have so far:

To be removed in version 3.11:
PyUnicode_EncodeUTF8
PyUnicode_EncodeUTF16

To be removed in version 3.12:
PyUnicode_GET_SIZE
PyUnicode_AS_UNICODE
PyUnicode_AS_DATA
PyUnicode_FromStringAndSize
PyUnicode_FromUnicode
PyUnicode_GetSize
PyUnicode_FromObject

Ref:
https://docs.python.org/3/c-api/unicode.html
https://docs.python.org/3/c-api/call.html