I would recommend reading the following article of Alan Storm regarding the difference between Php and Python
Some of the these aproach problems were overcome by introducing the namespace concept in php.
These differences are due to the development of the PHP language which was not a designed from start but evolved naturaly.
An example with namespaces in php showing how we can solve nowadays these fine pecularities
<?php
namespace Earth;
#File: hello_earth.php
function hello()
{
echo "Hello Earth! \n";
}
hello();
?>
<?php
namespace Mars;
#File: hello_mars.php
function hello()
{
echo "Hello Mars! Mind the germs. \n";
}
hello();
?>
<?php
namespace Solar;
include 'hello_earth.php';
include 'hello_mars.php';
echo "Starting up a solar system \n";
/* Usage with use
use Earth;
use Mars;
Earth\hello();
Mars\hello();
*/
\Earth\hello();
\Mars\hello();
?>