Use list.sort() when you want to mutate the list, sorted() when you want a new sorted object back. Use sorted() when you want to sort something that is an iterable, not a list yet. For lists, list.sort() is faster than sorted() because it doesn't have to create a copy. For any other iterable, you have no choice.
Here I would use the variable name "keyfun" instead of "cmpfun" to avoid confusion. The sort () method does accept a comparison function through the cmp= argument as well.
This is a strange answer because you do the sorting in-place but then the reversing out-of-place. If there is another variable aliasing the original list, its value afterwards will not have the elements in their original order, nor in descending order; the alias will point at a list sorted in ascending order. That could be rather surprising, and a source of subtle bugs.
And the sort method has a parameter, called key, which you can pass a function. Using this parameter, your list won't be ordered by the values of the list, but by the values of your function on the list.
Sort ascending vs. descending. Specify list for multiple sort orders. If this is a list of bools, must match the length of the by. As the default is ascending, and OP's goal is to sort ascending, one doesn't need to specify that parameter (see the last note below for the way to solve descending), so one can use one of the following ways:
As sort() sorts the list in place (ie, changes the list directly), it doesn't return the sorted list, and actually doesn't return anything, so your print statement prints None. If you saved your list to a variable, say x, called x.sort(), then print(x), you would see the sorted list.
Python has supported the key= for .sort since 2.4, that is year 2004, it does the Schwartzian transform within the sorting code, in C; thus this method is useful only on Pythons 2.0-2.3. all of which are more than 12 years old.
I am a bit confused regarding data structure in python; (),[], and {}. I am trying to sort a simple list, probably since I cannot identify the type of data I am failing to sort it. My list is simp...
Here's one way: You basically re-write your sort function to take a list of sort functions, each sort function compares the attributes you want to test, on each sort test, you look and see if the cmp function returns a non-zero return if so break and send the return value.
