另外,perl5.6及更高版本的sort使用Mergesort算法,而5.6之前的sort使用Quicksort算法,前者显然快于后者,所以,要想求速度,也要升级你的perl版本哦。 (三)CPAN上关于sort的一些模块 File::Sort-Sortoneormoretextfilesbylines Sort::Fields-Sortlinesusingoneormorecolumnsasthesortkey(s) Sort::ArbBiLex-Constructsort...
然后将其拆分为行，并将其输入Schwartzian变换（decorate-sort-undecorate），在此过程中反转日期格式--将...
,columns=['col2','col1']) print (unsorted_df) # 按标签排序 sorted_df = unsorted_df.sort...
reverse @a reverse @{$aref} 对一个数组做倒序排序 $a[3] ${$aref}[3] 数组中的一个成员 $a[3] = 17; ${$aref}[3] = 17 对一个成员赋值 上面每行中,两个表达式实现的是同一种功能。左边那个是对数组@a操作,右边那个是对'引用'$aref所指向的数组操作。它们对数组产生相同的作用。 使用哈希的...
matches only once, Failed matches don't reset the match variables Subroutine, Signal, Sorting Traps Barewords that used to look like strings look like subroutine calls, Reverse is no longer allowed as the name of a sort subroutine, "warn()" won't let you specify a filehandle OS Traps ...
$ perl -lane'$F[2]=reverse $F[2]=~tr/ATGC/TACG/r; print "@F"'test.txt ABC DEF CTAATC GHK ABC DEF GACGCC GHK ABC DEF GGAATT GHK Sort a CSV row How aboutsorting rows in csv file without header & first column? Here’s some simple comma-separated values: ...
return print reverse sort num values %array; return print(reverse(sort num (values(%array))); When in doubt, parenthesize. At the very least it will let some poor schmuck bounce on the % key invi. Even if you aren't in doubt, consider the mental welfare of the person who has to ...
1.7. Reversing a String by Word or Character Problem You want to reverse the words or characters of a string. Solution Use the reverse function in scalar context for flipping characters: $revchars = reverse($string); To flip words, use reverse in list context with split and join: $revwo...
Exchange values and keys of a hash - how to reverse a hash Manipulating Perl arrays: shift, unshift, push, pop Perl Arrays Reverse Polish Calculator in Perl using a stack Using a queue in Perl pop and push - video pwd Current working directory in Perl (cwd, pwd) How to ch...
Perl provides the function"sv_chop"to efficiently remove characters from the beginning of a string; you give it anSVand a pointer to somewhere inside thePV,and it discards everything before the pointer. The efficiency comes by means of a little hack: instead of actually removing the characters...