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0 pointsorblivion12y ago0 comments

I don't get the difference.

0 comments

They resolve differenti problems: say you have a list of complex object, and you wanna sort by an attribute, you can use

    mylist.sort(key=lambda element: element.attribute)

Elsewere, say you want to sort a non-omogeneous list, or according to a custom order (attribute1 descending, attribute2 ascending) cmp make this easy

philh12y ago

I think ve was saying, ve doesn't see the difference between python's `sort(key=...)` and perl6's `sort { one-arg block }`. (At any rate, I don't see that difference.)

rmc12y ago

Elsewere, say you want to sort a non-omogeneous list, or according to a custom order (attribute1 descending, attribute2 ascending) cmp make this easy

You can do this in python with the key function returning a list/tuple:

    mylist.sort(key=lambda element: (element.attribute1, -element.attribute2))

_ZeD_12y ago

I'm not sure you can do -"string" :)

dded12y ago

The Python .sort() method sorts in-place. The sorted() function returns a sorted copy, leaving the original untouched.

raiph12y ago

I realize this is drifting off topic, and I could well believe the current Rakudo implementation doesn't actually save the memory (I could believe it does, I just don't know) but P6, for any method, including sort:

    my $a = [2,1]; say $a.sort;  say $a # 1 2 2 1
    my $a = [2,1]; say $a.=sort; say $a # 1 2 1 2

This riffs off the general op= syntax:

    my $a = 1; say $a +  1; say $a # 2 1
    my $a = 1; say $a += 1; say $a # 2 2

orblivionOP12y ago

I meant I didn't understand the difference between Python's sort(key=..) and what's described here for Perl.

_ZeD_12y ago

what is described for perl is python's sort(cmp=...)

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0 comments

_ZeD_12y ago

They resolve differenti problems: say you have a list of complex object, and you wanna sort by an attribute, you can use

    mylist.sort(key=lambda element: element.attribute)

Elsewere, say you want to sort a non-omogeneous list, or according to a custom order (attribute1 descending, attribute2 ascending) cmp make this easy

philh12y ago

I think ve was saying, ve doesn't see the difference between python's `sort(key=...)` and perl6's `sort { one-arg block }`. (At any rate, I don't see that difference.)

rmc12y ago

Elsewere, say you want to sort a non-omogeneous list, or according to a custom order (attribute1 descending, attribute2 ascending) cmp make this easy

You can do this in python with the key function returning a list/tuple:

    mylist.sort(key=lambda element: (element.attribute1, -element.attribute2))

_ZeD_12y ago

I'm not sure you can do -"string" :)

dded12y ago

The Python .sort() method sorts in-place. The sorted() function returns a sorted copy, leaving the original untouched.

raiph12y ago

    my $a = [2,1]; say $a.sort;  say $a # 1 2 2 1
    my $a = [2,1]; say $a.=sort; say $a # 1 2 1 2

This riffs off the general op= syntax:

    my $a = 1; say $a +  1; say $a # 2 1
    my $a = 1; say $a += 1; say $a # 2 2

orblivionOP12y ago

I meant I didn't understand the difference between Python's sort(key=..) and what's described here for Perl.

_ZeD_12y ago

what is described for perl is python's sort(cmp=...)

1 more reply

j / k navigate · click thread line to collapse