Convert CSV to Multidimensional Associative Array

Question

I have a csv file with the following structure

name;timeframe;value1;value2;value3

The sample file looks like this

Abc;T1;V1,V2,V3
Abc;T2;V1,V2,V3
Abc;T3;V1,V2,V3
Xyz;T1;V1,V2,V3
Xyz;T2;V1,V2,V3
Xyz;T3;V1,V2,V3

The names can be repeated with different time frames, and there can be 8 different time frames.

What I want to do is to read this csv file in PHP and convert this into an Assosicative Multidimensional array. So that I can print it as a table later on

Name T1          T2           T3         
Abc  (v1,v2,v3)  (v1,v2,v3)   (v1,v2,v3)
Xyz  (v1,v2,v3)  (v1,v2,v3)   (v1,v2,v3)
Def  (v1,v2,v3)  (v1,v2,v3)   (v1,v2,v3)

So far I can read the csv file and print the individual rows and split them into separate fields. What I am stuck at is to use the associative arrays to hold this information in such a way that I can access it like

print($my_data_table['Abc']['T1'][V1])

Not sure what is the best way to create such structure. The reason I am interested in associated array is that the data is appended in the data file so with a new record at the end of the file it will be much easier to just replace the values of the corresponding entry in the existing array based on the 'Name' field in the record. This is my code so far

$f = fopen("scanner.txt", "r");
$names_array = array();
while (($line = fgetcsv($f)) !== false) {
        $row = $line[0];
        $cells = explode(";",$row);
        $names_array[$cells[0]] = array("T1","T2","T3");
        foreach ($cells as $cell) {
         //TODO: How to hold the values (v1,v2,v3) in specific cells of the data table   
        }
}
fclose($f);

Use the one-liner mentioned here: php.net/manual/en/function.str-getcsv.php $csv = array_map('str_getcsv', file('data.csv')); — Ultimater
– Ultimater, Commented Feb 7, 2019 at 3:37
Does it convert to associative array with a possibility of overwriting the old values? — Novice
– Novice, Commented Feb 7, 2019 at 3:42
Use the 2nd comment's code in the comments there if you need an associative array. It uses the one-liner along with the first row to use that as the keys. Note you'll have to adjust the delimiter. The "csv_to_array" function in the comments there looks like it would do what you need with the least amount of adjustments. — Ultimater
– Ultimater, Commented Feb 7, 2019 at 3:45

MihanEntalpo · Accepted Answer · 2019-02-07 05:19:54Z

1

1) fgetcsv could split lines by ";" by itself:

So, you can replace your while loop opening operator to the folowing:

while (($cells = fgetcsv($f, 0, ";")) !== false) {

And you wouldn't have to split line into cells manually.

2) You need a 2D - array, with every item contains (v1,v2,v3), so you could access it with instruction like $result[abc][T1] = (v1,v2,v3)

So, let's create it, and fill with data:

$result = [];
while (($cells = fgetcsv($f, 0, ";")) !== false) {
    // You have name in your first cell, right?
    $name = $cells[0];
    // And your timeframe in second one
    $timeframe = $cells[1];
    // v1, v2 and v3 are in third, fourth and fifth cells:
    $v123 = [$cells[2], $cells[3], $cells[4]];
    // And now put it into result:
    $result[$name][$timeframe] = $v123;
}

Now, to print as you need it:

// Printing header:
foreach ($result as $name => $result_by_name)
{ 
    echo "Name  ";
    foreach ($result_by_name as $timeframe => $v123)
    {
         echo $timeframe . "   ";
    }
    //End of header
    echo "\n";
    //exiting loop, as we need only 1 header
}

foreach ($result as $name => $result_by_name)
{ 
    echo $name . "    ";
    foreach ($result_by_name as $timeframe => $v123)
    {
        echo join(", ", $v123) . " ";
    }
    echo "\n";
}

Leaving good formatiing up to you :)

answered Feb 7, 2019 at 5:19

MihanEntalpo

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1 Comment

Novice Over a year ago

Fantastic. The only problem was the header, for some reason it does not print the header properly. Apart from that it works fine. I think the reason for that might be the header only represents one row in the csv and that does not contain the individual time frames (just a single value "TimeFrame").

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