[英]Read Hashes from Array in Perl
我是perl的新手(昨天晚上开始)。 我对哈希数组有问题。
以下情况:我有一个日志记录应用程序中的多个csv文件。 日志文件是每天创建的,实际上结构不好。 我想将它们分组在一起并显示一些统计数据。 读取和解析csv并不是一个真正的问题,但我想将列存储在哈希中以便于访问。 在csv文件中,secound列(PhysName)是要在其上对数据进行分组的列。 所以我认为,最好只将其他列保存在哈希中,将其中一些哈希保存在数组中,然后将数组保存在另一个哈希中,在这里我将PhysName作为键。
根本没什么大不了的:
my %dauerauftraege;
# Glob all CSV-Files in folder
my @files = glob("*.csv");
foreach my $file(@files) {
# read the file
open(DATA, "<$file") or die("Could not open File");
LINE:
foreach my $line(<DATA>) {
chomp($line);
if ($line eq "") {
next LINE;
}
# Split Line into Fields
my @line_data = split(";", $line);
my $phys_name = $line_data[1];
# skip the header file
if ($phys_name eq "PhysName") {
next LINE;
}
my %values =(
'date_time' => $line_data[0],
'sender' => $line_data[2],
'recipient' => $line_data[3],
'format' => $line_data[4],
'transport' => $line_data[5],
'partnername' => $line_data[6]);
push(\@{$dauerauftraege{"$phys_name"}}, \%values);
}
}
当我尝试使用print(Dumper(%dauerauftraege))
进行验证时,我得到以下信息:
$VAR1 = 'YYYYYYYXXXXXXXX';
$VAR2 = [
{
'transport' => 'FTP',
'format' => 'V1',
'partnername' => 'A_TEST',
'date_time' => '2016.07.25 11:16:52',
'sender' => 'BBB',
'recipient' => 'CCC'
},
{
'recipient' => 'CCC',
'sender' => 'BBB',
'partnername' => 'A_TEST',
'date_time' => '2016.07.25 11:17:15',
'format' => 'V1',
'transport' => 'FTP'
}
];
$VAR3 = 'XXXXXXXYYYYYYYY';
$VAR4 = [
{
'format' => 'V2',
'partnername' => 'S_TEST',
'date_time' => '2016.07.25 10:15:02',
'recipient' => 'DDD',
'sender' => 'AAA',
'transport' => 'HTTP'
},
{
'transport' => 'HTTP',
'recipient' => 'DDD',
'sender' => 'AAA',
'partnername' => 'S_TEST',
'format' => 'V2',
'date_time' => '2016.07.25 10:15:30'
}
];
我的第一个想法是,Dumper将奇数的$ VAR显示为键,将偶数的$ VAR显示为值,但是当我仔细查看偶数的$ VAR内的哈希后,我很确定我做错了什么同时将内部哈希(带有列和值)插入存储在%dauerauftraege
哈希中的数组中。
因此,现在从散列中读取数据时,在此处包含带有此代码的哈希数组
# Get the keys to iterate over them
my @dauerauftraege_keys = keys(%dauerauftraege);
print("count dauerauftraege: ".(scalar @dauerauftraege_keys)."\n");
# iterate over the keys to get the array of hashes
foreach my $dauerauftrag_key (@dauerauftraege_keys) {
# retrive the array
my @dauerauftrag = $dauerauftraege{"$dauerauftrag_key"};
print("count hashes inside the array: ".(scalar @dauerauftrag)."\n");
# iterate over the hashes and print the values
foreach my $dauerauftrag_values (@dauerauftrag) {
print(%{$dauerauftra_values}{'date_time'});
print("\n");
print(%{$dauerauftra_values}{'sender'});
print("\n");
print(%{$dauerauftra_values}{'recipient'});
print("\n");
print(%{$dauerauftra_values}{'format'});
print("\n");
print(%{$dauerauftra_values}{'transport'});
print("\n");
print(%{$dauerauftra_values}{'partnername'});
print("\n");
}
}
我总是得到这个错误:
count dauerauftraege: 2
count hashes inside the array: 1
Use of uninitialized value in print at ./LastRun_Evaluation.pl line 56, <DATA> line 5.
Use of uninitialized value in print at ./LastRun_Evaluation.pl line 57, <DATA> line 5.
Use of uninitialized value in print at ./LastRun_Evaluation.pl line 58, <DATA> line 5.
Use of uninitialized value in print at ./LastRun_Evaluation.pl line 59, <DATA> line 5.
Use of uninitialized value in print at ./LastRun_Evaluation.pl line 60, <DATA> line 5.
Use of uninitialized value in print at ./LastRun_Evaluation.pl line 61, <DATA> line 5.
date_timesenderrecipientformattransportpartnernamecount hashes inside the array: 1
Use of uninitialized value in print at ./LastRun_Evaluation.pl line 56, <DATA> line 5.
Use of uninitialized value in print at ./LastRun_Evaluation.pl line 57, <DATA> line 5.
Use of uninitialized value in print at ./LastRun_Evaluation.pl line 58, <DATA> line 5.
Use of uninitialized value in print at ./LastRun_Evaluation.pl line 59, <DATA> line 5.
Use of uninitialized value in print at ./LastRun_Evaluation.pl line 60, <DATA> line 5.
Use of uninitialized value in print at ./LastRun_Evaluation.pl line 61, <DATA> line 5.
date_timesenderrecipientformattransportpartnername
这使我相信,我的问题在以下行中:
push(\@{$dauerauftraege{"$phys_name"}}, \%values);
当我仔细阅读此行时,我了解以下内容: $dauerauftraege{"$phys_name"}
我返回一个skalar( $
),其中包含对该数组的引用,该引用由@{}
取消了对该数组的引用。 现在,使用\\%values
我将对values
Hash的引用传递给push
,将其添加到对数组的引用中,该引用由@前面的\\
表示。
如果有人可以帮助我解决这个问题,我将非常高兴。 谢谢很多人:-)
似乎您不太了解如何取消引用数据结构。 看看下面的代码,我对它们进行了一些修改,以期使事情变得更加清晰:
my @keys = keys(%dauerauftraege);
for my $key (@keys) {
print "*** $key ***\n";
my $aref = $dauerauftraege{$key};
for my $values_href (@$aref){
print "$values_href->{date_time}\n";
print "$values_href->{sender}\n";
print "$values_href->{recipient}\n";
print "$values_href->{format}\n";
print "$values_href->{transport}\n";
print "$values_href->{partnername}\n";
}
print "\n";
}
我认为问题在于您如何访问数据结构。 尝试这个:
my @dauerauftraege_keys = keys %dauerauftraege;
print("count dauerauftraege: ".(scalar @dauerauftraege_keys)."\n");
# iterate over the keys to get the array of hashes
foreach my $dauerauftrag_key (@dauerauftraege_keys) {
# retrieve the array
my $dauerauftrag = $dauerauftraege{"$dauerauftrag_key"}; # ref to array
my @a = @$dauerauftrag;
print("count hashes inside the array: ".(scalar @a)."\n");
# iterate over the hashes and print the values
foreach my $dauerauftrag_values (@a) { # also a reference
print $dauerauftrag_values->{'date_time'} . "\n";
print $dauerauftrag_values->{'sender'} . "\n";
print $dauerauftrag_values->{'recipient'} . "\n";
print $dauerauftrag_values->{'format'} . "\n";
print $dauerauftrag_values->{'transport'} . "\n";
print $dauerauftrag_values->{'partnername'} . "\n";
}
}
始终use strict;
并use warnings;
。 它们有助于避免错别字和其他问题。
%dauerauftraege
是一个哈希,您试图像数组一样访问它。 您正在尝试遍历哈希,同时在整个哈希的每次迭代中进行打印。
我认为代码可能看起来像这样:
use strict;
use warnings;
my %dauerauftraege;
# Glob all CSV-Files in folder
my @files = glob("*.csv");
foreach my $file(@files) {
# read the file
open(my $fh, "<", $file) or die("Could not open File");
LINE:
foreach my $line(<$fh>) {
chomp($line);
next LINE unless($line);
# Split Line into Fields
my @line_data = split(";", $line);
my $phys_name = $line_data[1];
# skip the header file
next LINE if ($phys_name eq "PhysName");
@{$dauerauftraege{"$phys_name"}}
{'date_time', 'sender', 'recipient',
'format', 'transport', 'partnername'}=@line_data[0,2..6];
}
}
并打印...
# Get the keys to iterate over them
my @dauerauftraege_keys = keys(%dauerauftraege);
print("count dauerauftraege: ".(scalar @dauerauftraege_keys)."\n");
# iterate over the keys to get the array of hashes
foreach my $dauerauftrag_key (@dauerauftraege_keys) {
print "\n$dauerauftrag_key:\n";
print join("\n",
@{$dauerauftraege{"$dauerauftrag_key"}}{'date_time','sender','recipient',
'format','transport','partnername'})."\n";
}
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