Python or PHP for web development ?

Yes PHP has one of the largest communities and has a very nice support from the community, and Python is better in terms of usability (lines of code), stability , performance, and it's less dirty in term of coding style than PHP.
If you are going to develop a web-site, close your eyes and go with PHP I'm saying that because in most of the sites the strength of python can't be utilized.
In large sites "Really big sites" PHP isn't an option mainly because it's a very slow language, Facebook left PHP , and went with HipHop PHP, twitter said a good bye to PHP and went Ruby and scala.
In the other hand Google, youtube has many components built on python.

i think both are good languages they are interpreted, high level languages with dynamic typing it depends on the developer and the solution but in my opinion PHP is better , because of huge sociaty & huge installed user base

PHP is extremely popular but Python is extremely better

I Think PHP is very simple, familiar with multi platform and fast for running.
PHP is too familiar to web based application like facebook.com and Web CMS platform developped based on PHP such Wordpress,Joomla,Drupal etc.
PHP most popular because have largest communities.
in webhosting provider (commercial and free) "in cpanel" web application on based PHP programming is very easy to running than another based progamming leaguage.
php is also easy if combined with other scripts such as Ajax or jquery.
But in Secure system, Phyton is Better.

PHP for web development is better, and I think Python and Perl are designed for backend.
If you interested to see Python for web, there are many frameworks such as Django.

Python..
django is just the easiest way to get going and even though there is a lot of php code out there, that doesn't mean its the best place to start.
django is just so robust and easy to build robust applications with that i simply couldn't recommend php unless you specifically need to run an existing php code base.

This is complete comparison of python vs php by Python team.
http://wiki.python.org/moin/PythonVsPhp

I use PHP for we development .
And i use python for background jobs and tasks.

Most definitely PHP. It is the best and most flexible server side language.

php is used more for web development, but there are websites that use python.

WORDPRESS, JOOMLA, CODELGNITER