\documentclass[a4paper,french]{article}
\usepackage[T1]{fontenc}
\usepackage{babel}
\usepackage[margin=1cm]{geometry}
\usepackage{xcolor}
\usepackage{enumitem}
\input{insbox}
\usepackage{listings}

\lstdefinestyle{mypython}{
        language=Python,
        tabsize=4,
        numberstyle=\tiny,
        columns=flexible,
        backgroundcolor=\color{black!05},
        showstringspaces=true,
        literate=
            {à}{{\`a}}1
            {â}{{\^a}}1
            {é}{{\'e}}1
            {è}{{\`e}}1
            {ê}{{\^e}}1
            {ë}{{\"e}}1
            {î}{{\^i}}1
            {ô}{{\^o}}1
            {ù}{{\`u}}1
            {«}{{\og}}1
            {»}{{\fg{}}}1
}

\usepackage[most]{tcolorbox}
\begin{document}

\begin{tcblisting}{
  colback=white,
  colframe=white,
  comment and listing,
  sidebyside,
  listing style=mypython,
  comment={
    \begin{enumerate}
    \item question 1...
    \item question 2...
    \item question 3...
    \end{enumerate}
  }
}
def f(x):
  y=x**2-x+3
  return(y)
\end{tcblisting}

\end{document}