Sort a list in python

问题:

I have this list

[1,-5,10,6,3,-4,-9]

But now I want the list to be sorted like this:

[10,-9,6,-5,-4,3,1]

As you can see I want to order from high to low no matter what sign each number has, but keeping the sign, is it clear?

回答1:

Use abs as key to the sorted function or list.sort:

>>> lis = [1,-5,10,6,3,-4,-9]
>>> sorted(lis, key=abs, reverse=True)
[10, -9, 6, -5, -4, 3, 1]

回答2:

Use:

    l.sort(key= abs, reverse = True)

Lists can be sorted using the sort() method. 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.

In your case, you should use the abs() function, which will return the absolute value of your list elements. So, your list

>>> l = [1,-5,10,6,3,-4,-9]

Will be sorted like it was

>>>  [abs(1),abs(-5),abs(10),abs(6),abs(3),abs(-4),abs(-9)]

Which should be:

>>> [1 ,-4 ,-5 ,6 ,-9 ,10]

To order from the biggest to the smalles, use the reverse=True parameter also.