Not to take a stand, just FYI: PHP5 has built-in iterator support now and PHP 5.3 includes namespace support as well (TBR this month).
But, PHP5's iterator is broken. The only way you can use it is in a foreach loop. In Python, iterators can be used with any iterative construct.
Namespace support in PHP never really bothered me, but I've occasionally run into problems with name clashes with built in functions. It'll be welcomed anyway for sure.
Here are a few Python language features that I seriously miss when I'm working in PHP:
- Modules and namespaces! This is the feature that initially drove me away from PHP.
- List comprehensions (let you construct a new list based on an old list in a one-liner)
- Built in iterator support (easy "for item in collection" support for many different types of collection)
- First class functions and closures (so you can treat your functions as data)
Those are just four off the top of my head. If you haven't looked at Python before (but already know how to program) I suggest taking a look at http://diveintopython.org/ which is a free online book.