On 01/08/14 06:12, memilanuk wrote:
counts = {'a':1, 'b':22, 'c':100}
then counts.get('b') should return 22. I got that much.
And counts.get is just an uncalled version of that:
foo = counts.get
foo('b')
should return 22 as well. Think I got that as well.
Well done, thats the crux of it.
Where things are going pear-shaped is how counts.get can function as a
'key' when we don't actually supply () (or anything inside them)
The max() function calls the key function internally.
Here is a trivial example (untested code!)
>>> def f(aFunc):
for n in range(3):
print("Your function returns",aFunc(n),"with input",n)
>>>
>>> def g(n):
return n+2
>>>
>>> f(g)
Your function returns 2 with input 0
Your function returns 3 with input 1
Your function returns 4 with input 2
So f calls aFunc using n internally.
The specification of f requires that you pass it a function that accepts
a single argument
max and sort etc work the same way.
They call your function internally.
--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.flickr.com/photos/alangauldphotos
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