Overriding append method after inheriting from a Python List

Question

I want to create a list that can only accept certain types. As such, I\'m trying to inherit from a list in Python, and overriding the append() method like so:

Answer 1

You can also use build-in array class. It works only with numeric types, but is probably best solution for such cases. It is optimized to minimize memory usage.

Example:

from array import array
array('c', 'hello world')     # char array
array('u', u'hello \u2641')   # unicode array
array('l', [1, 2, 3, 4, 5])   # long array
array('d', [1.0, 2.0, 3.14])  # double array

You can perform the same operations as with normal list:

chars = array('c')            
chars.extend('foo')

But when you try to insert other type then specified, an exception is raised:

>>> chars.extend([5,10])
Traceback (most recent call last):
   File "", line 1, in 
TypeError: array item must be char  

For all available types look here