How to Write Fast Python Code

Описание: This short highlights a quirk of Python that enables a Python program to run at much faster speeds than typical user-space Python code.

There are multiple implementations of the Python interpreter in different programming languages, including but not limited to C and Java (In case you're unfamiliar, languages are either written in other programming languages or in assembly language - a topic for another day).

When installing C-Python on your computer, you're actually installing a C program on your computer that eventually is compiled into a specific path in your computer like /usr/bin/python3. It is at compilation time that builtin functions, like list and map, are implemented in C-Python, meaning those functions are written in C, which makes them much faster.

This video benchmarks two functions that append to a list in Python: one using a Python for loop, and the other using builtin functions list and map. The latter implementation ends up being 40% faster than the prior.

Note: although this video shows a method of increasing your Python code's speed, the technique is not an excuse to avoid asymptotic analysis and to figure out asymptotically better methods of writing functions.