function set_val(array &$arr, $path,$val)

{

   $loc = &$arr;

   foreach(explode('.', $path) as $step)

   {

     $loc = &$loc[$step];

   }

   return $loc = $val;

}

Dot notation works fine unless we stump upon few special cases such as

•   If the variable contains a dot(.), colon(:), starting 

or ending with an underscore or any known public attribute.

•   If there’s a collision between methods and attributes of python dictionaries.

•   Array notation also allows for dynamic variable composition.

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