CODEWITHSUNDEEP
pythonlistmethods
augusti
augusti

Reputation: 411

List of methods

I wonder if its possible to create a list (or something) of methods. For example, lets say I have a list 

 lst = []

And I want to have specific methods e.g. insert, remove and stuff. And I would like to call those, randomly from the list, so that I can add something like lst.add(3, 4) but selecting the methods from the list of methods. Its silly, but its like I would like to do this: lst.listofmethods[3]

Possibly, the methods maybe should be stored in a dictionary instead?

Upvotes: 2

Views: 94

Answers (3)

willeM_ Van Onsem
willeM_ Van Onsem

Reputation: 476584

Well there are two things that pop into mind:

  • dir(..) returns you a list of the names of the methods. You can then use getattr(..) to get the attribute that listens to the given name. For example:

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

    So if you want to call append (index 34), you could using:

    getattr(lst,dir(lst)[34])('a')

  • You can construct a list of methods like:

    listofmethods = [lst.append,lst.clear]

    and then call it with:

    listofmethod[1]()

    to call clear() on the list.

    of course you can also define a dictionary that works almost equivalent:

    dicofmethods = {'foo':lst.append,'bar':lst.clear}

    and call with:

    dicofmethods['foo'](42)

Upvotes: 3

Simeon Aleksov
Simeon Aleksov

Reputation: 1335

You can store functions into dictionary as well.

>>> def foo():
...     print("foo")
... 
>>> def bar():
...     print("bar")
... 
>>> 
>>> foobar = {"foo": foo, "bar" : bar}
>>> foobar["foo"]()
foo
>>> foobar["bar"]()
bar
>>> foobar["bar"]
<function bar at 0x7f0561c6eae8>
>>>

Upvotes: 3

Jacques de Hooge
Jacques de Hooge

Reputation: 6990

Yes, you can store functions in a list, like this:

def f ():
    print ('f')

def g ():
    print ('g')

aList = [f, g]

for aFunction in aList:
    aFunction ()

Upvotes: 2

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