Call Class Method From Another Class

Question

In Python  is there a way to call a class method from another class  I am attempting to spin my own MVC framework in Python and I can not figure out how to invoke a method from one class in another class   Here is what I want to happen   class A      def method1 arg1  arg2             do code here  class B      A method1 1 2    I am slowly getting into Python from PHP so I am looking for the Python equivalent of PHP s call user func array

User · Answer

Just call it and supply self  class A      def m self  x  y           print x y   class B      def call a self           A m self  1  2   b   B   b call a     output  3

User · Answer

class CurrentValue       def   init   self  value           self value   value      def set val self  k           self value   k      def get val self           return self value   class AddValue       def av self  ocv           print  Before    ocv get val            num   int input  Enter number to add               nnum   num   ocv get val           ocv set val nnum          print  After add     ocv get val      cvo   CurrentValue 5   avo   AddValue    avo av cvo    We define 2 classes  CurrentValue and AddValue We define 3 methods in the first class         One init in order to give to the instance variable self value an initial value         A set val method where we set the self value to a k         A get val method where we get the valuue of self value We define one method in the second class     A av method where we pass as parameter ovc  an object of the first class We create an instance  cvo  of the first class We create an instance  avo  of the second class We call the method avo av cvo  of the second class and pass as an argument the object we have already created from the first class  So by this way I would like to show how it is possible to call a method of a class from another class   I am sorry for any inconvenience   This will not happen again   Before  5   Enter number to add   14   After add   19

User · Answer

update   Just saw the reference to call user func array in your post  that s different  use getattr to get the function object and then call it with your arguments  class A object       def method1 self  a  b  c             foo  method   A method1   method is now an actual function object  that you can call directly  functions are first class objects in python just like in PHP   5 3    But the considerations from below still apply  That is  the above example will blow up unless you decorate A method1 with one of the two decorators discussed below  pass it an instance of A as the first argument or access the method on an instance of A   a   A   method   a method1 method 1  2      You have three options for doing this   Use an instance of A to call method1  using two possible forms  apply the classmethod decorator to method1  you will no longer be able to reference self in method1 but you will get passed a cls instance in it s place which is A in this case  apply the staticmethod decorator to method1  you will no longer be able to reference self  or cls in staticmethod1 but you can hardcode references to A into it  though obviously  these references will be inherited by all subclasses of A unless they specifically override method1 and do not call super    Some examples   class Test1 object     always inherit from object in 2 x  it s called new-style classes  look it up     def method1 self  a  b           return a   b       staticmethod     def method2 a  b           return a   b       classmethod     def method3 cls  a  b           return cls method2 a  b   t   Test1      same as doing it in another class  Test1 method1 t  1  2   form one of calling a method on an instance t method1 1  2           form two  the common one  essentially reduces to form one  Test1 method2 1  2    the static method can be called with just arguments t method2 1  2         on an instance or the class  Test1 method3 1  2     ditto for the class method  It will have access to the class t method3 1  2         that it s called on  the subclass if called on a subclass                          but will not have access to the instance it s called on                          if it is called on an instance    Note that in the same way that the name of the self variable is entirely up to you  so is the name of the cls variable but those are the customary values   Now that you know how to do it  I would seriously think about if you want to do it  Often times  methods that are meant to be called unbound  without an instance  are better left as module level functions in python

User · Answer

You can call a function from within a class with   A   method1

User · Answer

In Python function are first class citezens  so you can just assign it to a property like any other value  Here we are assigning the method of A s hello to a property on B  After   init    hello will be attached to B as self hello  which is actually a reference to A s hello  class A      def hello self  msg           print f quot Hello  msg  quot        class B      hello   A hello  print A hello  print B hello   b   B   b hello  quot good looking  quot    Prints   lt function A hello at 0x7fcce55b9e50 gt   lt function A hello at 0x7fcce55b9e50 gt  Hello good looking

[python] Call Class Method From Another Class

Examples related to python