Old-style and new-style classes in Python 2.7

python class python-2.7 new-style-class
User picture User · Dec 11, 2012 · Viewed 8.3k times · Source

Possible Duplicate:
Old style and new style classes in Python

What is the current state of affairs with new-style and old-style classes in Python 2.7?

I don't work with Python often, but I vaguely remember the issue. The documentation doesn't seem to mention the issue at all: The Python Tutorial: Classes. Do I still need to worry about this? In general, should I declare my classes like the following?

class MyClass:
    pass

or?

class MyClass(object):
    pass

Answer

Reinout van Rees picture Reinout van Rees · Dec 11, 2012

Always subclass "object". Those are new style classes.

  • You are ready for Python 3 that way.

  • Things like .super() work properly that way, should you need them.

Related questions

Getting attributes of a class

I want to get the attributes of a class, say: class MyClass(): a = "12" b = "34" def myfunc(self): return self.a using MyClass.__dict__ gives me a list of attributes and functions, and even functions like __module__ and __doc__. While MyClass().__…

Read More
AttributeError: 'datetime' module has no attribute 'strptime'

Here is my Transaction class: class Transaction(object): def __init__(self, company, num, price, date, is_buy): self.company = company self.num = num self.price = price self.date = datetime.strptime(date, "%Y-%m-%d") self.is_buy = is_buy And …

Read More
class method generates "TypeError: ... got multiple values for keyword argument ..."

If I define a class method with a keyword argument thus: class foo(object): def foodo(thing=None, thong='not underwear'): print thing if thing else "nothing" print 'a thong is',thong calling the method generates a TypeError: myfoo = foo() …

Read More