将另一个文件中的函数嵌入Python类

我有一些

commonfunctions

，可以作为不同类的方法重用。我将这些函数存储在模块目录中的commonfunctions.py文件中。我希望将函数嵌入到我需要的类中，并能够修改类的属性。我做了一些尝试，但没有一个是切实可行的。我想知道做这件事最好的方法是什么

commonfunctions.py

def mycommonfun(self,myarg):
    self.target = myarg+3

class mydummyclass(object):
    def mycommonfun(self,myarg):
        self.target = myarg+3

mainfile.py

import commonfunctions

class A(anotherclass):
   def __init__(self):
     self.target = None
   # not working
   commonfunctions.mycommonfun
class B(anotherclass):
   def __init__(self):
     self.target = None
     # I can't modify self.target
     self.mycommonfun = commonfunctions.mycommonfun
class C(anotherclass):
    # it works but it hides all the docstring
    def mycommonfun(self,myarg):
        commonfunctions.mycommonfun(self,myarg)

class D(anotherclas,commonfunctions.mydummyclass):
    pass #it works not sure why I have problem with hinting of the arguments

from commonfunction import ParentClass


class ChildClass(ParentClass):
    def __init__(self, target):
        super().__init__(target)


child = ChildClass(5) # self.target = 5
child.some_function(5) # self.target = 3 + 5 = 8

---

您需要做的是继承其他类方法

commonfunction.py

class ParentClass:
    def __init__(self, target):
        self.target = target

    def some_function(self, n):
        self.target = 3 + n

mainfile.py

import commonfunctions

class A(anotherclass):
   def __init__(self):
     self.target = None
   # not working
   commonfunctions.mycommonfun
class B(anotherclass):
   def __init__(self):
     self.target = None
     # I can't modify self.target
     self.mycommonfun = commonfunctions.mycommonfun
class C(anotherclass):
    # it works but it hides all the docstring
    def mycommonfun(self,myarg):
        commonfunctions.mycommonfun(self,myarg)

class D(anotherclas,commonfunctions.mydummyclass):
    pass #it works not sure why I have problem with hinting of the arguments

from commonfunction import ParentClass


class ChildClass(ParentClass):
    def __init__(self, target):
        super().__init__(target)


child = ChildClass(5) # self.target = 5
child.some_function(5) # self.target = 3 + 5 = 8