[Tutor] Dynamically calling a class

[jfouhy@paradise.net.nz]

Quoting Ryan Parrish <ryanpublic at foxracing.com>:

> example -
> 
> list_of_classes = ['A', 'B', B', 'A']
> 
> class A:
> 	doingsomething
> class B:
> 	doing something
> 
> for x in list_of_classes:
> 	x()
> 
> my problem is that i get 'TypeError: 'str' object is not callable', of 
> which i understand what the error is saying, i just want to know how to
> dynamically call the class.

Just put the class object in the list!

>>> class A:
...  pass
...
>>> class B:
...  pass
...
>>> class C:
...  pass
...
>>> classes = [A, B, C]
>>> for cls in classes:
...  x = cls()
...  print x.__class__
...
__main__.A
__main__.B
__main__.C

You can do some black magic to go from the string 'A' to the class A (eg, use
eval()), but it's generally better to avoid that if you can.

-- 
John.