'list' Values are Objects

Q

Are "list" values objects in Python?

✍: FYIcenter.com

A

Yes, "list" values are objects in Python. In fact, all data values in Python are objects.

In Python, "list" is defined as an object class with the following interesting properties, constructors, and methods:

list.__doc__ - Property holding a short description of "list" objects.

list.__new__() - Constructor returning a "list" object. It can be invoked as list(). For example:

>>> list.__new__(list)
[]
>>> list()
[]
>>> list(("Age", 25))
['Age', 25]
>>> list(["Age", 25])
['Age', 25]
>>> list("FYIcenter.com")
['F', 'Y', 'I', 'c', 'e', 'n', 't', 'e', 'r', '.', 'c', 'o', 'm']

list.__getitem__() - Instance method for the [] operation, returning item of the list at the given position. For example:

>>> ['Age', 25].__getitem__(1)
25
>>> ['Age', 25][1]
25
>>> (['Age', 25])[1]
25

list.__len__() - Instance method returning the number of items in the list. It can be invoked as len(list). For example:

>>> ['Age', 25].__len__()
2
>>> len(['Age', 25])
2

list.__sizeof__() - Instance method returning the size of the list in memory, in bytes. For example:

>>> ['Age', 25].__sizeof__()
28
>>> [].__sizeof__()
20

list.append() - Instance method appending a new value to the end of the list. For example:

>>> a = ['Age', 25]
>>> a.append(["Name","Joe"])
>>> a
['Age', 25, ['Name', 'Joe']]
>>>

You can use the dir(list) function to see all members of the "list" class:

>>> dir(list)
['__add__', '__class__', '__contains__', '__delattr__', '__delitem__', 
'__dir__' , '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', 
'__getitem__' , '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', 
'__init_subclass__',  '__iter__', '__le__', '__len__', '__lt__', '__mul__', 
'__ne__', '__new__', '__r educe__', '__reduce_ex__', '__repr__', 
'__reversed__', '__rmul__', '__setattr__' , '__setitem__', '__sizeof__', 
'__str__', '__subclasshook__', 'append', 'clear',  'copy', 'count', 'extend', 
'index', 'insert', 'pop', 'remove', 'reverse', 'sort ']

 

Understanding Data Values as Objects

⇒⇒Python Tutorials

2017-09-12, 117👍, 0💬