PYTHON array_merge

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Python replacement for PHP's array_merge [ edit | history ]
For the simple case (concatenating lists with numeric keys):
list1 + list2

For merging associative arrays:
result = dict(dict1)
result.update(dict2)

or
result = dict(dict1, **dict2)


In Python 3:
def array_merge( first_array , second_array ):
	if isinstance( first_array , list ) and isinstance( second_array , list ):
		return first_array + second_array
	elif isinstance( first_array , dict ) and isinstance( second_array , dict ):
		return dict( list( first_array.items() ) + list( second_array.items() ) )
	elif isinstance( first_array , set ) and isinstance( second_array , set ):
		return first_array.union( second_array )
	return False

PHP array_merge

PHP original manual for array_merge [ show | php.net ]

array_merge

(PHP 4, PHP 5)

array_mergeMerge one or more arrays

Description

array array_merge ( array $array1 [, array $array2 [, array $... ]] )

Merges the elements of one or more arrays together so that the values of one are appended to the end of the previous one. It returns the resulting array.

If the input arrays have the same string keys, then the later value for that key will overwrite the previous one. If, however, the arrays contain numeric keys, the later value will not overwrite the original value, but will be appended.

If only one array is given and the array is numerically indexed, the keys get reindexed in a continuous way.

Parameters

array1

Initial array to merge.

array

Variable list of arrays to recursively merge.

Return Values

Returns the resulting array.

Examples

Example #1 array_merge() example

<?php
$array1 
= array("color" => "red"24);
$array2 = array("a""b""color" => "green""shape" => "trapezoid"4);
$result array_merge($array1$array2);
print_r($result);
?>

The above example will output:

Array
(
    [color] => green
    [0] => 2
    [1] => 4
    [2] => a
    [3] => b
    [shape] => trapezoid
    [4] => 4
)

Example #2 Simple array_merge() example

<?php
$array1 
= array();
$array2 = array(=> "data");
$result array_merge($array1$array2);
?>

Don't forget that numeric keys will be renumbered!

Array
(
    [0] => data
)

If you want to completely preserve the arrays and just want to append them to each other (not overwriting the previous keys), use the + operator:

<?php
$array1 
= array();
$array2 = array(=> "data");
$result $array1 $array2;
?>

The numeric key will be preserved and thus the association remains.

Array
(
    [1] => data
)

Warning

The behavior of array_merge() was modified in PHP 5. Unlike PHP 4, array_merge() now only accepts parameters of type array. However, you can use typecasting to merge other types. See the example below for details.

Example #3 array_merge() PHP 5 example

<?php
$beginning 
'foo';
$end = array(=> 'bar');
$result array_merge((array)$beginning, (array)$end);
print_r($result);
?>

The above example will output:

Array
(
    [0] => foo
    [1] => bar
)

See Also