The difference is that in PHP, the developers of "Stuff\Mail" and "Tools\Mail" would have to define "Stuff" and "Tools" as the namespace for their code. In Pyt

The difference is that in PHP, the developers of "Stuff\Mail" and "Tools\Mail" would have to define "Stuff" and "Tools" as the namespace for their code. In Python, they don't have to do anything. The project that uses the code decides.