Question

I know PHP a little. But Python is totally new for me. I only know it’s something “similar”, right? Or wrong? What are the differences I should know?

Answer 1

This page on the Python wiki highlights the main
differences and the common elements between Python and PHP:

Compared as Languages

What strengths does PHP have that Python doesn’t?

• the ‘switch’ statement and ‘do … while’ construct.
• increment and decrement and assignment operators (assignment is a statement only in Python).
• the ternary operator/statement (… ? … : …).
  • Retort: Python 2.5 has conditional expressions.
• an expedient (commonly installed) environment
• one array type that doubles as a list and a dictionary. Dictionary keys are iterated in their original order.
• private, protected and public modifiers for both properties and methods abstract and final modifiers for both classes and methods
  interfaces.
  • Note: as Python has multiple inheritance, there’s less
    need for interfaces. Also Python 2.6 has introduced Abstract Base
    Classes.
• variable variables
• default arguments in functions
• embedding in HTML (Note: mod_python has this as well).
• a wide range of byte-code caches available.

What weaknesses does PHP have that Python doesn’t?

• (more verbose) syntax from C/C++ and Perl, with lots curly braces and dollar signs and “->”-s
• confused tableau of function names. The builtin library has a wide variety of naming conventions. Functions often have prefixes to denote
  their source (but often not). Functions are often placed into classes
  to simulate namespaces.
• a somewhat weak type system (not to be confused with dynamic types).

What does Python have that PHP doesn’t?

• indentation is used to mark out block structure rather than curly braces.
  • Retort: PHP curly braces make it work with HTML more easy.
• modules
• Rules that help catching typos more; reading an undefined variable is an error, it’s not silently treated as if it was null.
  • Retort: PHP will issue E_NOTICE. This will be shown in a develop environment.
    • Counter-retort: It’s still dangerous in production environment. As of the development, it’s extra hassle to configure, watch logs,
      etc., when it could just stop, as you are supposed to eliminate these
      problems anyway. That PHP still has the more easy-going approach is
      probably because people have utilized undefined vars a lot in existing
      code base, so they couldn’t fix this.

• a small core (language or runtime?)

  • retort: it is not entirely true (substance needed)

• very clear, concise, and orthogonal syntax

• keyword arguments (i.e., parameters passed by name instead of by position) to functions and methods, easy support for default arguments

  • Retort: PHP have default arguments

    • Counter-retort: Defaults are much less useful without keyword arguments

• true object orientation and ‘first class’ classes and functions

  • Retort: OO has been completely revamped in PHP 5

    • Counter-retort: But it’s still painful, obviously a hack

• classes are used extensively in the standard library.

  • Retort: PHP 5 has SPL which is fully class-based

• multiple inheritance

• object-oriented file handling

• excellent introspection

  • Retort: PHP 5 Reflection

  • Counter-retort: We said excellent introspection

• everything is a reference! (references are painful in PHP)

  • Retort: Not in PHP 5

  • Counter-retort: note that arrays are still passed around by value (unless you add an explicit &)

  • Retort: You won’t accidentally modify it.

• consistent case sensitivity (PHP functions are case insensitive, but variables are case sensitive)
• a simple array slicing syntax

• iterators

  • Retort: in PHP 5

• structured exception handling

  • Retort: in PHP 5

  • Counter-retort: where are PHP 5’s equivalent of else and finally?

  • Counter-retort 2: unfortunately most standard PHP functions don’t use exceptions for reporting errors, which makes structured
    exception handling much less useful

• ‘finally’ made it in PHP 5.5 operator overloading

  • Retort: In PHP you can use runkit extension to emulate the same feature

  • Counter-retort: “In PHP you have to use runkit extension to emulate the same feature”

• SWIG integration

• threading

  • Retort: Python have Global Interpreter Lock so it’s not really parallel

• “with … as” statement to deal with resources that need closing reliably and concisely

• an excellent profiler

  • Retort: XDebug, a debugging and profiling extension, that supports both PHP4 and PHP5 is extremely popular lots of high-level
    data types (lists, tuples, dicts, DateTimes, NumPy arrays, etc.)

  • Retort: PHP had SPL Types which is included in PHP5 as a standard library

• differentiation between arrays (lists) and associative arrays (dictionaries).

  • Retort: PHP array is more flexible. In case developer want a true array, just use FixedArray in PHP SPL

• support for all major GUI frameworks

• strong internationalization and UNICODE support

  • Retort: PHP 6 will include Unicode support. This feature is available in PHP5.2 and PHP5.3 via intl extension which can be found
    at pecl.php.net

  • Retort: PHP have mbstring for Unicode

• tends to lead to much more scalable applications — importing modules is safer than textually including code as in PHP: global
  variables are not used to exchange information.

Compared as Web Development Frameworks

Unlike PHP, which has web development features built directly into the
core language, Python’s web development capabilities are provided by
add-on modules. Basic CGI capabilities are provided by the ‘cgi’
module which comes in Python’s standard library. There’s also a wide
range of third-party modules available for Python; some are
complementary, others compete. As a result, Python provides a more
flexible base for web development.

There are some adverse side effects of this flexibility. First, the
range of choices can be bewildering. Unless you are working
experienced Python web developers, PHP is easier to get started with.
Second, support for PHP is more common with shared-hosting companies
than support for the various Python options.

Another difference is that PHP is embedded in the web server, whereas
Python web applications can either be embedded in the web server like
PHP or run in a separate process. Here’s a simple classification of
Python web development platforms:

• emdedded in the web server process
  • Apache modules (eg. mod_python) embed the Python interpreter in Apache and allow other Apache modules to be written with Python. This
    is the same idea as mod_perl.
  • PyWX is an extension to AOLServer that serves the same purpose as the Apache modules above.
  • MS ASP scripts can be written using Python via Active Scripting Host.
• running in a separate process
  • non-persistent process (a new process is spawned for each request)
    • custom CGI scripts
  • persistent process (all requests are sent from the web server to one persistent process)
    • custom Fast-CGI scripts
    • ‘Application Servers’ (eg. Zope, Webware, SkunkWeb)

(Note: It’s possible to write a long-running server in PHP, but there
are precious few examples of it.)

The vast majority of Python Web applications are run in a separate
process. This has some important implications.

Security

PHP has historically had a horrible history when it comes to security.
See the following article as an example:
http://old.lwn.net/2001/0704/a/study-in-scarlet.php3 (Note: This
article was published 10 years ago, and is no longer valid for more
than an idea of PHPs history with security).

Community Support

PHP:

• huge installed user base, but the figures are probably distorted by shared hosting
• low signal-to-noise ratio — because PHP is so expedient, many of the users are not invested in the technology (or even their own code)
  or the community

Python:

• sizable, but not huge, installed user base
• Python Software Foundation
• lots of specialized interest groups
• very high signal-to-noise ratio

Commercial Support

PHP

http://www.zend.com

Python

See the
CommercialServices
page for more information.