CODEWITHSUNDEEP
python
Ethan Bierlein
Ethan Bierlein

Reputation: 3535

Calling functions from a list issue

I am making a project that involves calling functions from a list, but I can't get it to work straight. There is some problem with calling the functions from the list, and I just can't seem to figure out why. I have some code below for an example, and the output will be provided as well. The code provided is just an example of the basic idea of what I am trying to do. It is not my actual code. Don't worry though, it is the basic idea.

import random, time
def word1():
    print "Hello"

def word2():
    print "Goodbye"

words = [word1(), word2()]

def run():
    while True:
        random.choice(words)()
        time.sleep(0.5)
run()

And the output I get is this:

TypeError: 'NoneType' object is not callable

For all I know, this could be some simple error that I am overlooking, but for the life of me, can not figure out. Help!

Upvotes: 1

Views: 65

Answers (3)

mgilson
mgilson

Reputation: 309929

You're storing the function results in the list1, not the functions themselves.

i.e. change:

words = [word1(), word2()]

to:

words = [word1, word2]

1And the results are all None which is why you get the NoneType not callable error...

Upvotes: 2

jwodder
jwodder

Reputation: 57480

"word1()" is not the function word1; it is instead the return value from calling word1(), which, because word1 doesn't explicitly return anything, is None. What's word1? It's just word1. Thus, the declaration of words should be changed from:

words = [word1(), word2()]

to:

words = [word1, word2]

Upvotes: 3

kojiro
kojiro

Reputation: 77107

You call the functions already within the list. You want to defer.

words = [word1, word2]
def run():
  while True:
    random.choice(words)()
    time.sleep(0.5)

Upvotes: 1

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