First, let’s briefly introduce the two languages.

• PHP
  PHP (Hypertext Preprocessor) is an open-source scripting language designed specifically for web development. It powers a staggering 76% of all websites whose server-side language is known, including leading sites like Facebook and Wikipedia.
  
  Created in 1995, PHP has grown to become the most popular backend language. Its flexibility, simplicity, and tight focus on the web make it a preferred choice for many web application development companies.
• Python
  Python, first released in 1991, is a general-purpose high-level programming language. It powers around 3% of all websites, including sites like Instagram and Spotify.
  
  While not only focused on web development, Python’s simple and readable syntax has made it a popular choice for larger and more complex web apps. Its versatility and large ecosystem of libraries have enabled it to excel in data science, machine learning, and other domains too.
  
  Now that we have a quick intro to PHP and Python, let’s explore them in-depth across various factors.

PHP has been the backbone of web development for decades. A few key stats about its popularity:

• PHP powers a staggering 76% of all websites whose server-side programming language is known. This dominance reflects its long history and specialized focus on the web.
• It powers 74.4% of the top 1 million websites. This includes leading sites like Facebook, Wikipedia, and WordPress.
• PHP has over 7 million developers worldwide and its ecosystem keeps growing.

Python may not rival PHP’s sheer dominance, but it has rapidly emerged as a rock-solid backend choice:

• Python powers around 3% of all websites whose server-side language is known.
• It powers 3.9% of the top 1 million websites, including Instagram and Spotify.
• With over 12 million developers, Python has a thriving and growing community.

• PHP is more popular for smaller, content-heavy sites. Its web-focused libraries and simplicity make PHP a pragmatic choice for common applications like blogs, e-commerce stores, and company sites where fast prototyping is key.
• Python is gaining popularity for large web apps with complex functionality and processing needs. Its versatility makes it great for web applications that involve machine learning or data analytics.

• Performance
  Performance is critical for a good user experience. Let’s see how PHP vs Python compare.
• PHP’s Speed
  

  PHP is optimized specifically for the web, so it’s very fast for typical requests:

  • PHP scripts are processed faster than Python generally, often twice as fast.
  • Built-in functions help cache content and queries, improving speed.
  • PHP keeps variable types loose, reducing overhead during processing.

Python takes a more flexible approach:

• It provides optional static typing to make larger programs more efficient.
• Performance varies by framework. Some frameworks like PyPy offer significant speed boosts.
• Python supports concurrency and parallelism for complex tasks.

Both PHP and Python can scale to support enterprise-level web applications with proper architecture:

• Facebook uses a mix of PHP and Python to run its massive infrastructure.
• Frameworks like Laravel (for PHP) and Django (for Python) make it easy to scale applications.
• Cloud platforms like AWS and Azure allow PHP and Python apps to be scaled easily.

The ecosystem of frameworks and tools around a language determines how quickly and easily you can build applications. Let’s contrast PHP vs Python’s ecosystems.

• PHP Frameworks
  

  PHP has a rich ecosystem of specialized web development frameworks:

  • Laravel – The most popular PHP framework, with an expressive syntax and robust features for web apps.
  • Symfony – A full-stack framework with great performance and stability.
  • CodeIgniter – A lightweight and easy-to-learn framework.
  • CakePHP – A framework promoting rapid application development and conventional software patterns.
  These frameworks provide common needs for web development like routing, ORM, and authentication out of the box so developers can focus on application logic.
• Python Frameworks
  

  For Python, the most popular web frameworks are:

  • Django – The most commonly used Python web framework with powerful admin capabilities.
  • Flask – A lightweight framework great for smaller apps.
  • Pyramid – Built to be very flexible to handle different types of projects.
  • Web2py – Focused on rapid app development and ease of use.
  Python web frameworks provide similar benefits around routing and abstraction. Overall there are fewer frameworks compared to PHP, but the top ones like Django and Flask are very full-featured.

Both languages provide robust surrounding ecosystems:

• PHP has tools like Composer for dependency management and PHPUnit for testing.
• Python has extremely extensive libraries for needs like data analysis via NumPy and Pandas.
• There are also shared tools like Swagger for API development and Docker for containerization.

PHP historically suffered from several security problems:

• The loose typing resulted in unexpected behavior that opened vulnerabilities.
• PHP applications and frameworks contained insecure defaults.
• Rampant issues like SQL injection plagued early PHP apps.

However, modern PHP has evolved significantly:

• PHP 7 and 8 have hardened security with built-in encryption and SQL escaping mechanisms.
• Frameworks like Laravel make it easier to implement security best practices.
• The PHP security team frequently identifies and patches vulnerabilities.

Python has generally been viewed as a secure language:

• Python’s concentration on code readability results in fewer unexpected behaviors.
• The language and its libraries provide strong tools for encryption, sanitization, and more.
• Python’s more deliberate style encourages secure coding practices.
• The Python security response team also works to identify CVEs and release fixes.

PHP’s ubiquity makes it well-supported across diverse platforms, enabling strong scalability:

• PHP applications can scale by adding caching layers like Redis and Varnish.
• Load balancing can distribute traffic across multiple PHP application servers.
• Cloud platforms like AWS and Azure allow PHP apps to quickly grow.

Similarly, Python provides great capabilities for scalability:

• Python applications can leverage CDNs and caching solutions.
• Its support for asynchronous processing makes it very scalable.
• Python also scales well on cloud platforms like AWS, Azure, and Google Cloud.
• Python frameworks emphasize high performance and concurrency.

As a scripting language designed for the web, PHP offers a gentle learning curve for newcomers:

• Simple and familiar syntax borrowed from languages like C and Perl.
• Wide range of beginner tutorials and courses available online.
• Ability to insert PHP code directly into HTML.
• Lots of pre-built libraries so less code needs to be written.

Python was designed from the ground up to be easily readable and learned:

• The neat and consistent syntax uses natural whitespace instead of brackets.
• Focus on code readability and explicitness.
• Simpler and fewer language constructs than many other languages.
• Plentiful tutorials and documentation available for beginners.

PHP’s popularity translates to plentiful job opportunities:

• PHP developer was the 2nd most in-demand tech job in 2022 according to TechRepublic.
• The average salary for PHP developers in the US is $110,000 per year, higher than many other languages.
• There were over 15,000 PHP job listings on Indeed at the time of writing.
• High demand across roles like PHP web developer, Laravel developer, WordPress development roles, etc.

Python developers are also in high demand:

• Python developer was the 6th most in-demand tech job in 2022 per TechRepublic.
• The average salary for Python developers is over $105,000 in the US.
• There are over 19,000 current Python job openings on Indeed, reflecting the demand.
• Roles are more varied, including backend developer, data scientist, machine learning engineer, etc.

PHP shines when used for:

• Building content-heavy websites like blogs, news sites, etc.
• E-commerce sites and applications.
• Social networking sites and forums.
• CRM and other enterprise web apps.
• Shared hosting environments like those used by small businesses.
• Quickly building MVPs and prototypes.

Python stands out when used for:

• Developing complex web applications with lots of code.
• Data analysis and data science applications.
• Machine learning and AI systems.
• Building web services and APIs.
• Adding automation and scripting capabilities to projects.
• Scientific computing and numeric analysis applications.

In summary:

• PHP – Best for typical web applications from blogs to e-commerce development, especially where fast prototyping is required.
• Python – Best for complex programs and applications beyond just web development. Excellent for advanced applications involving machine learning etc.