I have the following perl code in where I have a perl structure as follows:
`
use Data::Dumper;
my %data = (
'status' => 200,
'message' => '',
'response' => {
'name' => 'John Smith',
'id' => '1abc579',
'ibge' => '3304557',
'uf' => 'XY',
'status' => bless( do{\(my $o = 1)}, 'JSON::PP::Boolean' )
}
);
my $resp = $data{'status'};
print "Response is $resp \n";
print Dumper(%data->{'response'});
Getting the status field works, however If I try something like this:
my $resp = $data{'response'}
I get Response is HASH(0x8b6640)
So I'm wondering if there's a way I can extract all the data of the 'response' field on the same way I can do it for 'status' without getting that HASH...
I've tried all sort of combinations when accessing the data, however I'm still getting the HASH back when I try to get the content of 'response'
$data{'response'} is the correct way to access that field on a hash called %data. It's returning a hash reference, which prints out by default in the (relatively unhelpful) HASH(0x8b6640) syntax you've seen. But if you pass that reference to Dumper, it'll show you everything.
print Dumper($data{'response'});
to actually access those subfields, you need to dereference, which is done with an indirection -> operation.
print $data{'response'}->{'name'}
The first access doesn't need the -> because you're accessing a field on a hash variable (i.e. a variable with the % sigil). The second one does because you're dereferencing a reference, which, at least in spirit, has the $ sigil like other scalars.
Thanks for your posts. I fixed the code as follows:
use Data::Dumper;
my %data = (
'status' => 200,
'message' => '',
'response' => {
'name' => 'John Smith',
'id' => '1abc579',
'ibge' => '3304557',
'uf' => 'XY',
'status' => bless( do{\(my $o = 1)}, 'JSON::PP::Boolean' )
}
);
my $resp = $data{'response'};
print Dumper($resp);
Now it works like a charm, and I'm able to get the data I want.
I have a CSV file, which contains data like below:
I want parse data from above csv file and store it in a hash initially. So my hash dumper %hash would look like this:
$VAR1 = {
'1' => {
'Name' => 'Name1',
'Time' => '7/2/2020 11:00'
'Cell' => 'NCell1',
'PMR' => '1001',
'ISD' => 'ISDVAL1',
'PCO' => 'PCOVAL1'
},
'2' => {
'Name' => 'Name2',
'Time' => '7/3/2020 13:10',
'Cell' => 'NCell2',
'PMR' => '1002',
'PCO' => 'PCOVAL2',
'MKR' => 'MKRVAL2',
'STD' => 'STDVAL2'
},
'3' => {
'Name' => 'Name3',
'Time' => '7/4/2020 20:15',
'Cell' => 'NCell3',
'PMR' => '1003',
'ISD' => 'ISDVAL3',
'MKR' => 'MKRVAL3'
},
};
Script is below:
#!/usr/bin/perl
use strict;
use warnings;
use Text::CSV;
use Data::Dumper;
my %hash;
my $csv = Text::CSV->new ({ binary => 1, auto_diag => 1 });
open my $fh, "<:encoding(utf8)", "input_file.csv" or die "input_file.csv: $!";
while (my $row = $csv->getline ($fh)) {
my #fields = #$row;
$hash{$fields[0]}{"Time"} = $fields[1];
$hash{$fields[0]}{"Name"} = $fields[2];
$hash{$fields[0]}{"Cell"} = $fields[3];
}
close $fh;
print Dumper(\%hash);
Here id is an key element in each line and based on the data value each data should be stored in respective names of an id.
Problem here is, till column D (Cell) I am able to parse data in above script and there after column D there won't be a header line and it will be like column E will act as header and column F is the value for the particular header's particular id. Similar condition goes to rest of the data values until end. And in middle we can see some values also will be missing. For example there is No MKR value for id 1.
How can I parse these data and store it in hash, so that my hash would look like above. TIA.
Changes made to the script posted was to remove the header line so that it does not form part of the result and added a for loop to set the reset of the data.
Test Data Used:
id,Time,Name,Cell,,,,,
1,7/2/2020 11:00,Name1,NCell1,PMR,1001,ISD,ISDVAL1
2,7/3/2020 13:10,Name2,NCell3,PMR,1002,PCO,PCOVAL2,MKR,MKRVAL2
Updated Script: (This was the first version suggest using the improved version in the edit)
#!/usr/bin/perl
use strict;
use warnings;
use Text::CSV;
use Data::Dumper;
my %hash;
my $csv = Text::CSV->new ({ binary => 1, auto_diag => 1 });
open my $fh, "<:encoding(utf8)", "input_file.csv" or die "input_file.csv: $!";
my $headers = $csv->getline ($fh);
while (my $row = $csv->getline ($fh)) {
$hash{$row->[0]}{Time} = $row->[1];
$hash{$row->[0]}{Name} = $row->[2];
$hash{$row->[0]}{Cell} = $row->[3];
for (my $i = 4; $i < scalar (#{$row}); $i += 2) {
$hash{$row->[0]}{$row->[$i]} = $row->[$i + 1];
}
}
close $fh;
print Dumper(\%hash);
Output:
$VAR1 = {
'2' => {
'MKR' => 'MKRVAL2',
'Name' => 'Name2',
'PCO' => 'PCOVAL2',
'Cell' => 'NCell3',
'Time' => '7/3/2020 13:10',
'PMR' => '1002'
},
'1' => {
'Name' => 'Name1',
'ISD' => 'ISDVAL1',
'Cell' => 'NCell1',
'Time' => '7/2/2020 11:00',
'PMR' => '1001'
}
};
Edit:
Thanks to comment from #choroba here is an improved version of the script setting the hash with all the additional row values first and then adding the first values Time Name Cell using the header line read from the file.
#!/usr/bin/perl
use strict;
use warnings;
use Text::CSV;
use Data::Dumper;
my %hash;
my $csv = Text::CSV->new ({ binary => 1, auto_diag => 1 });
open my $fh, "<:encoding(utf8)", "input_file.csv" or die "input_file.csv: $!";
my $headers = $csv->getline ($fh);
while (my $row = $csv->getline ($fh)) {
$hash{$row->[0]} = { #$row[4 .. $#$row] };
#{$hash{$row->[0]}}{#$headers[1, 2, 3]} = #$row[1, 2, 3];
}
close $fh;
print Dumper(\%hash);
There are some Text::CSV features that you can use to make this a bit simpler. There's a lot of readability to gain by removing density in the loop.
First, you can set the column names for missing header values. I don't know what those columns represent so I've called them K1, V1, and so on. You can substitute better names for them. How I do that isn't as important is that I do that. I'm using v5.26 because I'm using postfix dereferencing:
use v5.26;
my $headers = $csv->getline($fh);
my #kv_range = 1 .. 4;
$headers->#[4..11] = map { ("K$_", "V$_") } #kv_range;
$csv->column_names( $headers );
If I knew the names, I could use those instead of numbers. I merely change the stuff in #kv_range:
my #kv_range = qw(machine test regression ice_cream);
And, when the data file changes, I handle all of that here. When it's outside the loop, there's much less to miss.
Now that I have all columns named, I use getline_hr to get back a hash reference of the line. The keys are the column names I just set. This does a lot of the work for you already. You have to handle the pairs at the end, but that's going to be easy too:
my %Grand;
while( my $row = $csv->getline_hr($fh) ) {
foreach ( #kv_range ) {
no warnings 'uninitialized';
$row->{ delete $row->{"K$_"} } = delete $row->{"V$_"};
}
$Grand{ $row->{id} } = $row;
delete $row->#{ 'id', '' };
}
Now to handle the pairs at the end: I want to take the value in the column K1 and make it a key, then take the value in V1 and make that the value. At the same time, I need to remove those K1 and V1 columns. delete has the nice behavior in that it returns the value for the key you deleted. This way doesn't require any sort of pointer math or knowledge about positions. Those things might change and I've handled all of that before I got this far:
$row->{ delete $row->{"K$_"} } = delete $row->{"V$_"};
You could also do this in a couple steps if that statement is too much for you:
my( $key, $value ) = delete $row->#{ "K$_", "V$_" };
$row->{$key} = $value;
I'd leave the id column in there, but if you don't want it, get rid of it. Also, that step with the deletes might have made some empty string keys for the cells that had no values. Instead of guarding against that and making the foreach more complicated, I let it happen and get rid of it at the end:
delete $row->#{ 'id', '' };
Altogether, it looks like this. It's doing the same thing as Piet Bosch's answer, but I've pushed a lot of the complexity back into the module as well as doing a little pre-loop work:
use v5.26;
use strict;
use warnings;
use Data::Dumper;
use Text::CSV;
my $csv = Text::CSV->new({
binary => 1,
auto_diag => 1
});
open my $fh, "<:encoding(utf8)", "input_file.csv"
or die "input_file.csv: $!";
my $headers = $csv->getline($fh);
my #kv_range = 1 .. 4;
$headers->#[4..11] = map { ("K$_", "V$_") } #kv_range;
$csv->column_names( $headers );
my %Grand;
while( my $row = $csv->getline_hr($fh) ) {
foreach ( #kv_range ) {
no warnings 'uninitialized';
$row->{ delete $row->{"K$_"} } = delete $row->{"V$_"};
}
$Grand{ $row->{id} } = $row;
delete $row->#{ 'id', '' };
}
say Dumper( \%Grand );
And the output looks like this:
$VAR1 = {
'2' => {
'PMR' => '1002',
'PCO' => 'PCOVAL2',
'MKR' => 'MKRVAL2',
'Name' => 'Name2',
'Time' => '7/3/2020 13:10',
'Cell' => 'NCell3'
},
'1' => {
'Cell' => 'NCell1',
'Time' => '7/2/2020 11:00',
'ISD' => 'ISDVAL1',
'PMR' => '1001',
'Name' => 'Name1'
}
};
I have the following code for exporting all the items in one of my pods to json. The thing is I don't need all the 130 columns in the json file, but only about 20. Since this will be done for about 150 items I thought I could save some loading time by not printing out all the fields, but I do not know how to do this. For example I only want to print the column value named 'title' for all items in the pod. My code is attached bellow.
<?php
$pods = pods('name', array('orderby' => 'name asc', 'limit' => -1));
$all_companies = $pods->export_data();
if ( !empty( $all_companies ) ) {
die(json_encode($all_companies);
}else{
die(json_encode(array('error' => 'No cars found.')));
}
?>
I thought about doing something like this:
if ( 0 < $all_companies->total() ) {
while ($all_companies->fetch()) {
$json .= $all_companies->field('title');
}
$json = rtrim($json, ",");
$json .= '}}';
}
echo $json;
But it doesn't work and also the code becomes very long.
I'd make an array of the names of the twenty fields you want then build an array of those fields for each item, by doing a foreach of those field names passed to Pods::field() inside the while loop. Like this:
$pods = pods('name', array('orderby' => 'name asc', 'limit' => -1));
$fields = array( 'field_1', 'field_2' );
if ( $pods->total() > 0 ) {
while ( $pods->fetch() ) {
foreach ( $fields as $field ) {
$json[ $pods->id() ] = $pods->field( $field );
}
}
$json = json_encode( $json );
}
Alternatively, you could hack the /pods/<pod> endpoint of our JSON API to accept a list of fields to return as the body of the request. Wouldn't be hard to do, make sure to submit a pull request if you make it work.
I have Dumper outputting data correctly:
'Apps' => [
\{
'name' => '1'
},
\{
'name' => '2'
},
\{
'name' => '3'
},
\{
'name' => '4'
},
\{
'name' => '5'
},
\{
'name' => '6'
},
\{
'name' => '7'
}
],
'code' => 'SUCCESS'
};
But when I convert it to JSON I have a lot of problems:
my #jsonapps;
my #apps = map { $_ } keys %glob;
my %hash;
$hash{'code'} = 'SUCCESS';
for (#apps) {
my $app = { 'name' => $_ };
push (#jsonapps, \$app);
}
# $hash{'Apps'} = \#jsonapps;
my $jsonfinal = encode_json \%hash;
print $jsonfinal;
It definitely has to do when with I try to add an array of hashes in:
$hash{'Apps'} = \#jsonapps;
But I'm having a problem doing that since all the hashes have the same key "name". I need my output to look like:
{"code":"SUCCESS","Apps":[{"name":"1"},{"name":"2"},{"name":"3"},{"name":"4"},{"name":"5"},{"name":"6"},{"name":"7"}]}
Thanks, I appreciate the help - I've scoured everywhere to figure out how to do this, and I'm just banging my head against the wall now. Thanks!
Notice the extra \ in your dump output.
'Apps' => [
\{
'name' => '1'
},
This is because it they are references to hash references. The problem code is here:
for (#apps) {
my $app = { 'name' => $_ };
push (#jsonapps, \$app);
}
$app is already a hashref since you use braces and assign it to a scalar. But adding the \ in front when you push it to #jsonapps means you are pushing the reference to the hashref. You don't need to make it a reference because it is already a reference. You just need to omit the \.
for (#apps) {
my $app = { 'name' => $_ };
push (#jsonapps, $app);
}
I have a JSON that prints
{"d":{"success":true,"drivers":[{"FIRST_NAME":"JOHN","LAST_NAME":"SMITH"},{"FIRST_NAME":"JANE","LAST_NAME":"DOE"}]}}
The names change depending on what was found in the database. I need to push this in this format for each result resturned in the JSON:
push(#$dummy_data, {'name' => 'testname', 'key' => 'somekey-1234'});
push(#$dummy_data, {'name' => 'testname2', 'key' => 'somekey-5678'});
So for this example it would be John Smith in place of testname and Jane for testname2
How would I do this so for each first and last name in the json gets pushed in the format above?
Let's try this new game
use strict; use warnings;
use JSON::XS;
use Data::Dumper;
# creating reference to a void ARRAY
my $dummy_data = [];
# creating $json string
my $json = '{"d":{"success":true,"drivers":[{"FIRST_NAME":"JOHN","LAST_NAME":"SMITH"},{"FIRST_NAME":"JANE","LAST_NAME":"DOE"}]}}';
# converting JSON -> Perl data structure
my $perl_hash = decode_json $json;
# feeding $dummy_data ARRAY ref with a HASH
push #$dummy_data, {
name => $perl_hash->{d}->{drivers}->[0]->{FIRST_NAME},
key => $perl_hash->{d}->{drivers}->[1]->{FIRST_NAME}
};
# print what we have finally
print Dumper $dummy_data;
Output
$VAR1 = [
{
'name' => 'JOHN',
'key' => 'JANE'
}
];