Python as a PHP replacement?

» Python is more flexible than PHP

Python was engineered from the beginning to be a general purpose programming language. PHP on the other hand was written to overcome many of the "limitations" of the cgi-bin. This should say a lot about the "soul" of each language, but the conclusion I have come to is:

• PHP is meant to do web things really well
• Python is meant to do most things really well

Sure, these days you could write a desktop GUI in PHP, but it would most likely not be the right tool for the job (and you'd probably get laughed at). On a somewhat related note: many PHP developers I know find themselves switching between PHP for their website tasks, and a variety of other languages for other tasks (Shell Scripting for command-line scripts, Perl for text processing, etc.). As a Python programmer, I can typically stick to one programming language no matter what the task at hand requires (especially when armed with iPython).

Now, the obvious argument for PHP at this point is: "But wait, since PHP was written specifically for the web, shouldn't that actually give it more credibility as the right tool for the web job?" Well, 5 or 10 years ago I might have agreed with you, but web development has changed a lot in the past few years (not to mention the introduction of Python's WSGI spec).

The internet as a platform has grown and mutated drastically and now requires much more than "a server-side extension to HTML." We are now in an age of full-blown internet applications, which require a true "application-level" language. In my opinion, PHP has only recently begun to move in that direction with the v5.3 release (as well as updates expected in PHP 6). That alone should give you pause when pondering PHP's ability to "keep up" with the growth of the web.

In short, the internet continues to transform into an arena that is much less of a website platform, and much more of an application platform. To me, this makes a general purpose language such as Python the obvious choice for "future-proof" internet development.

» Python is typically faster than PHP

You might find PHP beating out Python in a simple "hello world"-type test, but "real-world" applications will typically run much faster in Python. In a Web 2.0 world where everyone has broadband, speed has become an important factor in keeping your visitors happy.

In addition to "raw, under-the-hood" speed, Python's language philosophy means it will typically scale better than PHP (although this can be argued a million different ways, since scalability usually involves much more than the language).

I've already done benchmarks comparing a few popular web frameworks, but if you're still curious I'd suggest you dig around with Google for a while.

» Python is easier to read and maintain than PHP

Any veteran programmer will tell you that code readability plays a huge factor in code maintainability. With that in mind, Python was designed with some pretty strict syntax rules in regards to code-blocks and whitespace. While this may initially frustrate programmers who are used to a looser "bracket-encapsulated" language, it actually forces you to write more readable (and therefore, more maintainable) code.

Other than readability, Python's clean syntax also means:

• You can write more code with less errors (because they're so easy to spot). This often comes as a pleasant surprise to programmers migrating from C-style languages (take Eric Raymond for example).
• You end up typing less — No more semicolons or brackets, and fewer parentheses.
• Your eyes don't have to move around as much to figure out what's going on.
• Your first guess about what's happening in a code-block is usually correct.

When you have time to kill, I'd recommend a stroll through Rosetta Code to compare how different languages "look" when tackling the same problem. Unless you just love brackets, I think you'll find the non C-style syntaxes much easier to read.

» Python is more consistent than PHP

Continuing somewhat in the vein of readability is the topic of consistency. Since PHP's lack of consistency has already been studied exhaustively by the Perl folks, I will spare you my rant and suggest you read theirs.

As a side note on this topic: I often hear PHP programmers talk about how awesome PHP's documentation is in that you can open a web browser and just type "php.net/some_function" to get help. Well, documentation recall usually isn't that big of a deal for me (because I have a somewhat photographic memory), but I will say that after switching to Python I found myself turning to its documentation significantly less than I had with PHP, simply because I didn't have to keep reminding myself whether that infrequently used function was named some_function or somefunction. With Python, the function/method I need is usually named exactly what I expect it to be named, and returns exactly what I expect it to return.

Oh, and don't even get me started on PHP's recent namespace decision.

However, PHP may still excel in a few areas

Having said all of that, there are a few areas where I believe PHP may still shine brighter than Python:

» PHP hosting support may be more prevalent than Python

It's practically unheard of to find yourself on a web host that doesn't support PHP out of the box. However, this is becoming less and less of an issue since most Python web applications can now be deployed using tools such as FastCGI or mod_proxy (as opposed to the popular mod_wsgi setup, which often requires root access to configure). These days any "reputable" web host is probably going to support some sort of strategy for deploying Python web applications. Of course, this only really applies to shared hosting environments without root access. If you've got a VPS or dedicated server you're fine.

» PHP is arguably "more seasoned" on the web than Python

The communities behind projects like Drupal and WordPress really stand out to me as examples of the maturity of PHP on the web. Although similar Python web projects have been slowly emerging (and Plone has been around for years, if that's your cup of tea), they don't really compete yet in my opinion.

Of course, I am only talking about specific web projects here. Language wise, Python has been around longer than PHP. Web 2.0 framework wise, Python's offerings have been around about as long as PHP's (pretty much every language had its own answer to Ruby on Rails in 2005).

» PHP seems easier than Python at first (and might be for simple deployments)

There's something magical about throwing together a few quick index.php/about.php/contact.php files and uploading them to the httpdocs directory of your webserver and it "just working." A lot of simple websites have no need for acronyms like MVC, ORM, and DRY, and in those cases PHP is an excellent "server-side extension" to HTML. However, if and when you begin to scale, you'll either find yourself switching to a full-blown framework, or throwing one together to help facilitate your growth. At that point, you'll probably begin discovering the "dark corners" of PHP, and may find yourself wishing you had "done it right" the first time.

So, which is better?

The most honest answer is probably: "It depends." Python definitely has some significant advantages over PHP in certain circumstances, but the same could probably be said of PHP in other circumstances (though mostly limited to the web I imagine).

Remember, the point of this post is to solidify the fact that Python can be an excellent PHP replacement. When it comes to programming languages, "better" is often more a case of personal preference than anything else. However, to me the points discussed above make Python the better choice when it comes to what I like in a web development language.

I hope this post has encouraged you PHP programmers out there to take another look at Python. It may take some getting used to (Python's way of doing things is inherently quite different than PHP's), but you will probably find yourself thanking me later.