PythonTeX

\documentclass{article}
\usepackage{pythontex}
\begin{document}
\section*{PythonTeX}

\emph{In this preview:} PythonTeX code is not run yet, so its results are missing; the code is shown as
written. A full run (latex, then pythontex, then latex again) runs the Python and puts the results in.

\begin{pycode}
from math import comb, factorial
rows = [[comb(n, k) for k in range(n + 1)] for n in range(6)]
\end{pycode}

Ten factorial is \py{factorial(10)}, and $\binom{10}{3}$ is \py{comb(10, 3)}.

The sixth row of Pascal's triangle: \py{rows[5]}.

\begin{pyverbatim}
def fib(n):
    a, b = 0, 1
    for _ in range(n):
        a, b = b, a + b
    return a
\end{pyverbatim}
\end{document}