projec/

|___model/

|      |___count.py

|      |___new_count.py

|___test.py

count.py

class A():
    def add(self,a,b):
        return a +b

from count import A
class B (A):
    def sub(self,a,b):
        return a-b
    
result =B().add(2,5)
print(result)

test.py

import sys
sys.path .append ("./model") #將model命令新增到系統環境變數下
from model import new_count

test =new_count.B()
test.add(2,4)
 

輸出結果：

=================================

7