这在 PHP 中可以相对容易地完成,不需要 Python 的 Pandas。
a.csv:
905,bla,meh?,na3
16,meh,meh?,ni2
4,bla,meh?,put1
b.csv:
4,info,meh1
16,info,meh2
905,info,meh3
<?php
// load both files to array
$a = array_map('str_getcsv', file('a.csv'));
$b = array_map('str_getcsv', file('b.csv'));
var_dump($a, $b);
// index both arrays by the column you want to merge by
$mergeColumn = 0;
$a = array_combine(array_column($a, $mergeColumn), $a);
$b = array_combine(array_column($b, $mergeColumn), $b);
var_dump($a, $b);
// construct combined array by combining same indexes from both arrays
// and merging the values (skip merge column from second file so it is not doubled)
$c = [];
foreach ($a as $k => $dataA) {
unset($b[$k][$mergeColumn]);
$c[$k] = array_merge($dataA, $b[$k]);
}
var_dump($c);
// put it to output csv file
$fp = fopen('c.csv', 'w');
foreach ($c as $row) {
fputcsv($fp, $row);
}
fclose($fp);
输出:
// a.csv as array
array(3) {
[0]=>
array(4) {
[0]=>
string(3) "905"
[1]=>
string(3) "bla"
[2]=>
string(4) "meh?"
[3]=>
string(3) "na3"
}
[1]=>
array(4) {
[0]=>
string(2) "16"
[1]=>
string(3) "meh"
[2]=>
string(4) "meh?"
[3]=>
string(3) "ni2"
}
[2]=>
array(4) {
[0]=>
string(1) "4"
[1]=>
string(3) "bla"
[2]=>
string(4) "meh?"
[3]=>
string(4) "put1"
}
}
// b.csv as array
array(3) {
[0]=>
array(3) {
[0]=>
string(1) "4"
[1]=>
string(4) "info"
[2]=>
string(4) "meh1"
}
[1]=>
array(3) {
[0]=>
string(2) "16"
[1]=>
string(4) "info"
[2]=>
string(4) "meh2"
}
[2]=>
array(3) {
[0]=>
string(3) "905"
[1]=>
string(4) "info"
[2]=>
string(4) "meh3"
}
}
// a.csv keyed by merge column
array(3) {
[905]=>
array(4) {
[0]=>
string(3) "905"
[1]=>
string(3) "bla"
[2]=>
string(4) "meh?"
[3]=>
string(3) "na3"
}
[16]=>
array(4) {
[0]=>
string(2) "16"
[1]=>
string(3) "meh"
[2]=>
string(4) "meh?"
[3]=>
string(3) "ni2"
}
[4]=>
array(4) {
[0]=>
string(1) "4"
[1]=>
string(3) "bla"
[2]=>
string(4) "meh?"
[3]=>
string(4) "put1"
}
}
// b.csv keyed by merge column
array(3) {
[4]=>
array(3) {
[0]=>
string(1) "4"
[1]=>
string(4) "info"
[2]=>
string(4) "meh1"
}
[16]=>
array(3) {
[0]=>
string(2) "16"
[1]=>
string(4) "info"
[2]=>
string(4) "meh2"
}
[905]=>
array(3) {
[0]=>
string(3) "905"
[1]=>
string(4) "info"
[2]=>
string(4) "meh3"
}
}
// combined array
array(3) {
[905]=>
array(6) {
[0]=>
string(3) "905"
[1]=>
string(3) "bla"
[2]=>
string(4) "meh?"
[3]=>
string(3) "na3"
[4]=>
string(4) "info"
[5]=>
string(4) "meh3"
}
[16]=>
array(6) {
[0]=>
string(2) "16"
[1]=>
string(3) "meh"
[2]=>
string(4) "meh?"
[3]=>
string(3) "ni2"
[4]=>
string(4) "info"
[5]=>
string(4) "meh2"
}
[4]=>
array(6) {
[0]=>
string(1) "4"
[1]=>
string(3) "bla"
[2]=>
string(4) "meh?"
[3]=>
string(4) "put1"
[4]=>
string(4) "info"
[5]=>
string(4) "meh1"
}
}
和 c.csv(结果):
905,bla,meh?,na3,info,meh3
16,meh,meh?,ni2,info,meh2
4,bla,meh?,put1,info,meh1
如果两个文件具有相同的标识符(第一列),则上述解决方案有效
如果在其他 csv 文件中可能存在不匹配的行,则需要另一种方法。
a.csv:
A,B,C,D
905,bla,meh?,na3
16,meh,meh?,ni2
4,bla,meh?,put1
1,a,b,c
b.csv:
A,Z,Y
4,info,meh1
16,info,meh2
905,info,meh3
2,d,e
a.csv 包含 A: 1 的行,在 b.csv 中没有匹配。 b.csv 包含 A: 2 的行,在 a.csv 中没有匹配项。
我们希望结果 csv 有 5 行(4、16、905 - common + 1 with empty Z,Y + 2 with empty B,C,D)。
代码:
<?php
$a = parseCsv('a.csv');
$b = parseCsv('b.csv');
$allHeaders = array_unique(array_merge($a['header'], $b['header']));
$mergeColumn = 'A';
$a['rows'] = array_combine(array_column($a['rows'], $mergeColumn), $a['rows']);
$b['rows'] = array_combine(array_column($b['rows'], $mergeColumn), $b['rows']);
$allIndexes = array_unique(array_merge(array_column($a['rows'], $mergeColumn), array_column($b['rows'], $mergeColumn)));
$c = [];
foreach ($allIndexes as $index) {
$row = [];
foreach ($allHeaders as $header) {
$row[$header] = '';
if (isset($a['rows'][$index][$header])) {
$row[$header] = $a['rows'][$index][$header];
} elseif (isset($b['rows'][$index][$header])) {
$row[$header] = $b['rows'][$index][$header];
}
}
$c[$index] = $row;
}
var_dump($c);
$fp = fopen('c.csv', 'w');
fputcsv($fp, $allHeaders);
foreach ($c as $row) {
fputcsv($fp, $row);
}
fclose($fp);
function parseCsv(string $file): array {
$rows = array_map('str_getcsv', file($file));
$header = array_shift($rows);
$csv = [];
foreach($rows as $row) {
$csv[] = array_combine($header, $row);
}
return ['header' => $header, 'rows' => $csv];
}
输出:
array(5) {
[905]=>
array(6) {
["A"]=>
string(3) "905"
["B"]=>
string(3) "bla"
["C"]=>
string(4) "meh?"
["D"]=>
string(3) "na3"
["Z"]=>
string(4) "info"
["Y"]=>
string(4) "meh3"
}
[16]=>
array(6) {
["A"]=>
string(2) "16"
["B"]=>
string(3) "meh"
["C"]=>
string(4) "meh?"
["D"]=>
string(3) "ni2"
["Z"]=>
string(4) "info"
["Y"]=>
string(4) "meh2"
}
[4]=>
array(6) {
["A"]=>
string(1) "4"
["B"]=>
string(3) "bla"
["C"]=>
string(4) "meh?"
["D"]=>
string(4) "put1"
["Z"]=>
string(4) "info"
["Y"]=>
string(4) "meh1"
}
[1]=>
array(6) {
["A"]=>
string(1) "1"
["B"]=>
string(1) "a"
["C"]=>
string(1) "b"
["D"]=>
string(1) "c"
["Z"]=>
string(0) ""
["Y"]=>
string(0) ""
}
[2]=>
array(6) {
["A"]=>
string(1) "2"
["B"]=>
string(0) ""
["C"]=>
string(0) ""
["D"]=>
string(0) ""
["Z"]=>
string(1) "d"
["Y"]=>
string(1) "e"
}
}
c.csv:
905,bla,meh?,na3,info,meh3
16,meh,meh?,ni2,info,meh2
4,bla,meh?,put1,info,meh1
1,a,b,c,,
2,,,,d,e