C language

Why is Python written in C and not C++

Python is written in C, specifically in the CPython implementation, rather than C++, for several practical and historical reasons. Here are the key factors behind this choice:

1. Simplicity and Efficiency

C is simpler and more lightweight than C++. While C++ offers additional features like classes, templates, and a richer standard library, this complexity comes at the cost of performance overhead in some cases. Python's primary goal is to remain simple and efficient, and C provides a sufficient low-level control over memory and performance without adding unnecessary complexity. C also allows for greater control over the hardware and system resources, which is important for building an interpreter that is lightweight and portable across a wide variety of platforms.

2. Portability

C has been widely used for creating cross-platform applications and system software, which means Python's CPython interpreter can easily be compiled and run on many different operating systems. C is supported on nearly all modern hardware, making it an ideal choice for ensuring Python's portability. Python needed to be available on a large variety of machines with minimal changes, and C, being so widely available and supported, made it the ideal choice for this.

3. Performance Considerations

While C++ might provide higher-level abstractions and some optimizations, it can introduce additional complexity and performance overhead, especially with features like object-oriented programming and exception handling. Python, being an interpreted language, prioritizes simplicity over maximum performance, so C’s straightforward and minimalistic nature aligns well with Python's design philosophy. CPython, being the default implementation, aims for optimal balance in terms of runtime performance. In many cases, Python’s performance bottlenecks are not necessarily in the C code, but in how Python handles object management and memory allocation. C offers a good enough level of control over performance for this.

4. Historical Reasons

When Python was first created by Guido van Rossum in the late 1980s and early 1990s, C was the language of choice for system-level programming and creating interpreters. The Python project needed to use a language that was efficient enough to create an interpreter, and at that time, C++ was not as widely adopted for system-level programming due to its more complex nature. Guido van Rossum initially wrote Python in C to benefit from C's existing ecosystem, including compilers, libraries, and runtime environments, which were more mature and accessible than C++ at the time.

5. Interfacing with C Libraries

One of Python’s strengths is its ability to easily interface with C libraries using the Python C API. Since Python is written in C, it can directly use C libraries without the need for extra wrappers or bindings. This makes Python highly extensible, especially for performance-critical tasks. Although it’s possible to interface Python with C++ (using tools like Boost.Python or pybind11), C’s simpler design makes it more natural and easier to integrate with Python.

6. C’s Longevity and Community

C has been around for a long time and has an extensive community and ecosystem of tools, libraries, and documentation. Many other successful projects, like Unix and many system utilities, were also written in C, making it a proven choice for implementing robust and reliable systems.

7. C++ Overhead

C++, while powerful, introduces more complexity than C, especially in terms of memory management, object-oriented features, and templates. This complexity is not needed for the Python interpreter, which primarily requires a language that can execute bytecode efficiently, manage objects, and handle system-level tasks without introducing excessive complexity. Additionally, C++’s extensive standard library could have introduced unnecessary overhead for the Python interpreter, which aims to be lean and efficient in its core implementation.

Conclusion

Python is written in C primarily because of its simplicity, efficiency, portability, and historical context. C++ may offer more advanced features, but Python's design philosophy of simplicity and readability meant that C was a more natural fit for creating the core interpreter. Moreover, the decision also stems from Python's need for a lean and efficient implementation that can run across many platforms with minimal complexity.