TypedList

class ipkiss3.all.TypedList

A list that ensures that all elements in it are of a given type.

The TypedList class can be used to create lists to which you can only add objects that are instances of a certain class. By default, TypedList allows all python objects. If you want to restrict to a certain type, you’ll have to extend TypedList.

The class below will for example only allow python strings:

class StrList(TypedList):
    _item_type = str

It’s important to note that TypedList and its subclasses are not real lists, at least not in the sense that it’s a subclass of the python list object:

>>> isinstance(TypedList([1, 2, 3]), list)
False

It does however have the same functionality of normal list, so you can append, update or slice the list as you could do with regular lists.

See also

TypedListProperty

Examples

>>> from ipkiss3 import all as i3
>>> class StrList(i3.TypedList):
...     _item_type = str
>>> abc = ['a', 'b', 'c']
>>> strlst = StrList(abc)
>>> strlst.append('d')
>>> strlst.extend(list('efg'))
>>> strlst[2:]
['c', 'd', 'e', 'f', 'g']

data

A member which allows list values.

Assigning to a list creates a copy. The orginal list will remain unmodified. This is similar to the semantics of the assignment operator on the C++ STL container classes.