How to sort list within a list?

Question

I want to sort my list based on the first item such as:

fruits = \
[['Mango', 6, 5, 8.0],
 ['Banana', 2.0, 5, 8.9, 7],
 ['Pineapple', 4, 6.8, 9],
 ['Apple', 3.9, 6, 7, 2]]

to be sorted out like this:

fruits = \
[['Apple', 3.9, 6, 7, 2],
 ['Banana', 2.0, 5, 8.9, 7],
 ['Mango', 6, 5, 8.0],
 ['Pineapple', 4, 6.8, 9]]

I know I have to use sort() function but I don't know how to use it in a right way to produce the outputs that I want.

Are the first elements of the lists strings? – Volatility May 02 '13 at 10:36 — Volatility, May 02 '13 at 10:36

score 1 · Accepted Answer · answered May 02 '13 at 10:42

1

What is your problem exactly? sort() already sorts by the first element.

In [14]: fruits = [["Mango", 6,5,8.0],
         ["Banana", 2.0,5,8.9,7],
         ["Pineapple", 4,6.8,9],
         ["Apple", 3.9,6,7,2]]

In [15]: fruits.sort()

In [16]: fruits
Out[16]: 
[['Apple', 3.9, 6, 7, 2],
 ['Banana', 2.0, 5, 8.9, 7],
 ['Mango', 6, 5, 8.0],
 ['Pineapple', 4, 6.8, 9]]

If your items are classes or variables, you should implement their comparison methods (__ge__, __le__, __gt__, __lt__) accordingly to your sorting needs.

Keep in mind that fruits.sort() modifies the list in place, if you want a new sorted copy, use sorted(fruits)

answered May 02 '13 at 10:42

fortran

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good point... I forgot that for a second – jamylak May 02 '13 at 10:44
@fortran how can I miss something like this? I am a really python noob. Thanks for this! – Fynn Mahoney May 02 '13 at 10:45
well, it happens... Python excels in clarity most of the time, but in this case a global function like `sorted` or a list method `sort` can be confusing. – fortran May 02 '13 at 10:47

How to sort list within a list?

1 Answers1