s...@uce.gov wrote:
How can I do something like this in python:

#!/usr/bin/python3.1

class MyNumbers:
  def __init__(self, n):
    self.original_value = n
    if n <= 100:
      self = SmallNumers(self)
    else:
      self = BigNumbers(self)

class SmallNumbers:
  def __init__(self, n):
    self.size = 'small'

class BigNumbers:
  def __init__(self, n):
    self.size = 'big'

t = MyNumbers(200)


When I do type(t) it says MyNumbers, while I'd want it to be BigNumbers, because BigNumbers and SmallNumbers will have different methods etc...

Do I need to use metaclasses?

Thanks.
You simply don't return inconsistent types with a return statement. This is a general rule in programming that has probably exceptions but regarding what you're saying, you clearly don't want to do that.

Immagine the following code:

oNumber = MyNumbers(random.int(100)) # note that oNumber is not a MyNumbers instance... quite confusing don't you think ? oNumber. ... wait a minute, which methods am I allowed to call ??? SmallNumbers adn BigNumbers have differents methods.

Some rules to follow, until you get some experience with python:
* use consistent types for method parameters.
* use consistent types for returned values.
* a class constructor should return an instance of that very same class.

JM
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