Question

我尝试在perl中将字符串转换为日期，但是会出错。

use strict; 
use warnings;  
use DateTime;  
use Date::Manip;

my $date = ParseDate("20111121");
print "today is ".$date->day_of_week."\n";

错误

Can't call method "day_of_week" without a package or object reference

看起来包导入有问题......

由于

Answer 1

DateTime不会解析日期。我会选择Time::Piece核心模块给你strptime（）：

#!/usr/bin/env perl
use strict;
use warnings;
use Time::Piece;
my $t = Time::Piece->strptime("20111121", "%Y%m%d");
print $t->strftime("%w\n");

Answer 2

DateTime本身没有解析工具，但有许多parsers可以对DateTime对象进行生成。大多数情况下，您可能需要DateTime::Format::Strptime。

use DateTime::Format::Strptime qw( );
my $format = DateTime::Format::Strptime->new(
   pattern   => '%Y%m%d',
   time_zone => 'local',
   on_error  => 'croak',
);
my $dt = $format->parse_datetime('20111121');

或者你可以自己做。

use DateTime qw( );
my ($y,$m,$d) = '20111121' =~ /^([0-9]{4})([0-9]{2})([0-9]{2})\z/
   or die;
my $dt = DateTime->new(
   year      => $y,
   month     => $m,
   day       => $d,
   time_zone => 'local',
);

Answer 3

从模块文档：This module does not parse dates

您需要添加I printed a date with strftime, how do I parse it again?中建议的代码，以便将字符串转换为日期时间对象。

perl如何将字符串转换为Datetime？

3 个答案: