Facts about Cython Programming Language

Cython is a programming language that is a superset of Python and can be compiled into C code for improved performance. Cython is developed to improve the execution speed and make the code faster compared to Python. In this article, we will look at some interesting facts about Cython Programming Language.

Cython can be used to speed up Python code

As the name suggests Cython is Python-like code that can be converted to C code for faster and improved execution speed. Developers can write code in Python which is then compiled into C code and makes the language much faster.

Example

In the below example, Cython code is nearly identical to the Python code, but the cpdef keyword tells Cython to compile the function to C code. This can result in a significant speedup, especially for computationally intensive tasks ?

# Python code
def fibonacci(n):
    if n <= 1:
        return n
    return fibonacci(n-1) + fibonacci(n-2)

print(fibonacci(3))

2

The equivalent Cython code with static typing ?

# Cython code (example.pyx)
cpdef int fibonacci(int n):
    if n <= 1:
        return n
    return fibonacci(n-1) + fibonacci(n-2)

Cython supports static typing

Cython supports static typing which means the variable type should be declared at compile time, unlike Python in which the variable's type can change at runtime. Static typing leads to faster code execution.

Example

In the below example, the Python code does not specify the type of variables a and b whereas in Cython code the variables are declared with specific integer data types ?

# Python code - no type specification
def add(a, b):
    return a + b

print(add(2, 3))

5

The equivalent Cython code with static typing ?

# Cython code with static typing (example.pyx)
cpdef int add(int a, int b):
    return a + b

Cython can interact with C code

Cython is designed to be compatible with C code, making it easy to integrate with existing C libraries. Cython code can be compiled into C code, which can then be linked with C code to create a single executable.

Example

In the below example, the hello_world() function is written in C code and declared as an external function in the Cython code ?

# C header file (hello.h)
void hello_world();

# C source file (hello.c)
#include <stdio.h>

void hello_world() {
    printf("Hello, world!\n");
}

# Cython code (example.pyx)
cdef extern from "hello.h":
    void hello_world()

def greet():
    hello_world()

Compilation Process

Cython code can be compiled into C code using the cythonize utility. Here's how to set up compilation ?

Example

# setup.py file for compiling Cython code
from distutils.core import setup
from Cython.Build import cythonize

setup(
    ext_modules = cythonize("example.pyx")
)

After running python setup.py build_ext --inplace, a compiled C module will be generated alongside the original Cython code ?

# Example usage after compilation
# This would work after proper compilation setup
result = 2 + 3
print(f"Result: {result}")

Result: 5

Key Benefits of Cython

Conclusion

Cython bridges the gap between Python's ease of use and C's performance. With static typing and direct C integration, Cython provides significant speed improvements while maintaining Python-like syntax for computational tasks.