Perl To Python Migration

SORTING SEQUENCES

In Perl we can place the sort function in front of any potential list to sort the results and if we want a sort ordered in the opposite direction then we can use the reverse function. All of the following are common occurrences:

sort @list;
sort keys %hash;
sort grep(/cat/,@names);
reverse sort getlistofcats();

We can of course also qualify the sort further by supplying a block or function to be used when comparing values, with $a and $b providing the two values that need to be compared:

sort { $a <=> $b } @list;
sort currency @money;

The only problem with the Perl solution is that we must make judgements at sort time about whether we are sorting numbers (in which case we use the <=> operator) or strings (when we use cmp ...