Python class returning value

Question

I m trying to create a class that returns a value  not self   I will show you an example comparing with a list    gt  gt  gt  l   list    gt  gt  gt  print l      gt  gt  gt  class MyClass   gt  gt  gt      pass   gt  gt  gt  mc   MyClass    gt  gt  gt  print mc  lt   main   MyClass instance at 0x02892508 gt    I need that MyClass returns a list  like list   does  not the instance info  I know that I can make a subclass of list  But is there a way to do it without subclassing   I want to imitate a list  or other objects     gt  gt  gt  l1   list    gt  gt  gt  l2   list    gt  gt  gt  l1     gt  gt  gt  l2     gt  gt  gt  l1    l2 True  gt  gt  gt  class MyClass    def   repr   self       return         gt  gt  gt  m1   MyClass    gt  gt  gt  m2   MyClass    gt  gt  gt  m1     gt  gt  gt  m2     gt  gt  gt  m1    m2 False   Why is m1    m2 False  This is the question   I m sorry if I don t respond to all of you  I m trying all the solutions you give me  I cant use def  because I need to use functions like setitem  getitem  etc

User · Answer

the worked proposition for me is   call   on class who create list of little numbers  import itertools      class SmallNumbers      def   init   self  how much           self how much   int how much          self work list     0    1    2    3    4    5    6    7    8    9           self generated list     0    1    2    3    4    5    6    7    8    9           start   10         end   100         for cmb in range 2  len str self how much     1               self ListOfCombinations is upper then start  is under then end  combinations cmb              start    10             end    10      def   call   self  number   args    kwargs           return self generated list number       def ListOfCombinations self  is upper then  is under then  combinations           multi work list   eval str  self work list      combinations          nbr   0         for subset in itertools product  multi work list               if is upper then  lt   nbr  lt  is under then                  self generated list append    join subset                   if self how much    nbr                      break             nbr    1  and to run it  if   name         main             sm   SmallNumbers 56          print sm generated list          print sm generated list 34   sm generated list 27   sm generated list 10           print  The Best   sm 15   sm 55   sm 49   sm 0    result   0    1    2    3    4    5    6    7    8    9    10    11    12    13    14    15    16    17    18    19    20    21    22    23    24    25    26    27    28    29    30    31    32    33    34    35    36    37    38    39    40    41    42    43    44    45    46    47    48    49    50    51    52    53    54    55    56   34 27 10 The Best 15 55 49 0

User · Answer

If what you want is a way to turn your class into kind of a list without subclassing list  then just make a method that returns a list   def MyClass        def   init   self           self value1   1         self value2   2      def get list self           return  self value1  self value2        gt  gt  gt print MyClass   get list    1  2       If you meant that print MyClass   will print a list  just override   repr     class MyClass                def   init   self           self value1   1         self value2   2      def   repr   self           return repr  self value1  self value2     EDIT  I see you meant how to make objects compare  For that  you override the   cmp   method   class MyClass        def   cmp   self  other           return cmp self get list    other get list

User · Answer

Use   new   to return value from a class    As others suggest   repr     str   or even   init    somehow  CAN give you what you want  But   new   will be a semantically better solution for your purpose since you want the actual object to be returned and not just the string representation of it   Read this answer for more insights into   str   and   repr   https   stackoverflow com a 19331543 4985585  class MyClass        def   new   cls           return list    or anything you want   gt  gt  gt  MyClass         Returns a true list not a repr or string

User · Answer

class MyClass        def   init   self  a  b           self value1   a         self value2   b      def   call   self           return  self value1  self value2    Testing    gt  gt  gt  x   MyClass  foo   bar    gt  gt  gt  x     foo    bar

User · Answer

I think you are very confused about what is occurring   In Python  everything is an object        a list  is an object  abcde   a string  is an object 1  an integer  is an object MyClass    an instance  is an object MyClass  a class  is also an object list  a type--much like a class  is also an object   They are all  values  in the sense that they are a thing and not a name which refers to a thing   Variables are names which refer to values   A value is not something different from an object in Python   When you call a class object  like MyClass   or list     it returns an instance of that class   list is really a type and not a class  but I am simplifying a bit here    When you print an object  i e  get a string representation of an object   that object s   str   or   repr   magic method is called and the returned value printed   For example    gt  gt  gt  class MyClass object           def   str   self                   return  MyClass              def   repr   self                   return  I am an instance of MyClass at address   hex id self         gt  gt  gt  m   MyClass    gt  gt  gt  print m MyClass      gt  gt  gt  m I am an instance of MyClass at address 0x108ed5a10  gt  gt  gt     So what you are asking for   I need that MyClass return a list  like list    not the instance info   does not make any sense   list   returns a list instance  MyClass   returns a MyClass instance  If you want a list instance  just get a list instance  If the issue instead is what do these objects look like when you print them or look at them in the console  then create a   str   and   repr   method which represents them as you want them to be represented   Update for new question about equality  Once again    str   and   repr   are only for printing  and do not affect the object in any other way  Just because two objects have the same   repr   value does not mean they are equal   MyClass      MyClass   because your class does not define how these would be equal  so it falls back to the default behavior  of the object type   which is that objects are only equal to themselves    gt  gt  gt  m   MyClass    gt  gt  gt  m1   m  gt  gt  gt  m2   m  gt  gt  gt  m1    m2 True  gt  gt  gt  m3   MyClass    gt  gt  gt  m1    m3 False   If you want to change this  use one of the comparison magic methods  For example  you can have an object that is equal to everything    gt  gt  gt  class MyClass object           def   eq   self  other                   return True       gt  gt  gt  m1   MyClass    gt  gt  gt  m2   MyClass    gt  gt  gt  m1    m2 True  gt  gt  gt  m1    m1 True  gt  gt  gt  m1    1 True  gt  gt  gt  m1    None True  gt  gt  gt  m1       True   I think you should do two things    Take a look at this guide to magic method use in Python  Justify why you are not subclassing list if what you want is very list-like  If subclassing is not appropriate  you can delegate to a wrapped list instance instead   class MyClass object       def   init   self           self  list          def   getattr   self  name           return getattr self  list  name           repr   and   str   methods are automatically created       for every class  so if we want to delegate these we must       do so explicitly     def   repr   self           return  MyClass  s     repr self  list      def   str   self           return  MyClass  s     str self  list    This will now act like a list without being a list  i e   without subclassing list     gt  gt  gt  c   MyClass    gt  gt  gt  c append 1   gt  gt  gt  c MyClass  1

User · Answer

You are describing a function  not a class   def Myclass        return

[python] Python class returning value

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